PR #21223: [nfc] Cleanup build files for expander transforms

Imported from GitHub PR #21223

This is part-3 of #18785 and #20595.

Motivation: Smaller build files, fewer merge conflicts, and convinience in development (more intuitive targets). For discussion surrounding this, check thread in #18785.
Copybara import of the project:

--
7832f84 by Shraiysh Vaishay <svaishay@nvidia.com>:

[nfc] Cleanup build files for expander transforms

This is part-3 of #18785 and #20595.

Motivation: Smaller build files, fewer merge conflicts, and convinience
in development (more intuitive targets). For discussion surrounding
this, check thread in #18785.

Merging this change closes #21223

FUTURE_COPYBARA_INTEGRATE_REVIEW=#21223 from shraiysh:cleanup_expander_transforms 7832f84
PiperOrigin-RevId: 715055989

xla/backends/interpreter/BUILD

@@ -39,10 +39,10 @@ cc_library(
         "//xla/hlo/ir:hlo",
         "//xla/hlo/ir:hlo_module_group",
         "//xla/hlo/pass:hlo_pass_pipeline",
-        "//xla/hlo/transforms:cholesky_expander",
-        "//xla/hlo/transforms:dynamic_index_splitter",
-        "//xla/hlo/transforms:eigh_expander",
-        "//xla/hlo/transforms:qr_expander",
+        "//xla/hlo/transforms/expanders:cholesky_expander",
+        "//xla/hlo/transforms/expanders:dynamic_index_splitter",
+        "//xla/hlo/transforms/expanders:eigh_expander",
+        "//xla/hlo/transforms/expanders:qr_expander",
         "//xla/service:batchnorm_expander",
         "//xla/service:compiler",
         "//xla/service:computation_placer",

xla/hlo/tools/hlo_opt/BUILD

@@ -34,28 +34,28 @@ cc_library(
         "//xla/hlo/analysis:indexed_array_analysis",
         "//xla/hlo/ir:hlo",
         "//xla/hlo/pass:hlo_pass_pipeline",
-        "//xla/hlo/transforms:cholesky_expander",
-        "//xla/hlo/transforms:comparison_expander",
         "//xla/hlo/transforms:convert_memory_placement_to_internal_annotations",
-        "//xla/hlo/transforms:convolution_4d_expander",
-        "//xla/hlo/transforms:convolution_pred_expander",
-        "//xla/hlo/transforms:dot_decomposer",
-        "//xla/hlo/transforms:dynamic_index_splitter",
-        "//xla/hlo/transforms:eigh_expander",
-        "//xla/hlo/transforms:logistic_expander",
         "//xla/hlo/transforms:operand_upcaster",
-        "//xla/hlo/transforms:optimization_barrier_expander",
-        "//xla/hlo/transforms:qr_expander",
-        "//xla/hlo/transforms:real_imag_expander",
-        "//xla/hlo/transforms:reduce_decomposer",
-        "//xla/hlo/transforms:reshape_decomposer",
-        "//xla/hlo/transforms:rng_expander",
-        "//xla/hlo/transforms:stable_sort_expander",
-        "//xla/hlo/transforms:stochastic_convert_decomposer",
         "//xla/hlo/transforms:while_loop_trip_count_annotator",
         "//xla/hlo/transforms/collectives:all_gather_broadcast_reorder",
         "//xla/hlo/transforms/collectives:all_reduce_contiguous",
         "//xla/hlo/transforms/collectives:collective_quantizer",
+        "//xla/hlo/transforms/expanders:cholesky_expander",
+        "//xla/hlo/transforms/expanders:comparison_expander",
+        "//xla/hlo/transforms/expanders:convolution_4d_expander",
+        "//xla/hlo/transforms/expanders:convolution_pred_expander",
+        "//xla/hlo/transforms/expanders:dot_decomposer",
+        "//xla/hlo/transforms/expanders:dynamic_index_splitter",
+        "//xla/hlo/transforms/expanders:eigh_expander",
+        "//xla/hlo/transforms/expanders:logistic_expander",
+        "//xla/hlo/transforms/expanders:optimization_barrier_expander",
+        "//xla/hlo/transforms/expanders:qr_expander",
+        "//xla/hlo/transforms/expanders:real_imag_expander",
+        "//xla/hlo/transforms/expanders:reduce_decomposer",
+        "//xla/hlo/transforms/expanders:reshape_decomposer",
+        "//xla/hlo/transforms/expanders:rng_expander",
+        "//xla/hlo/transforms/expanders:stable_sort_expander",
+        "//xla/hlo/transforms/expanders:stochastic_convert_decomposer",
         "//xla/hlo/transforms/simplifiers:all_reduce_folder",
         "//xla/hlo/transforms/simplifiers:batch_dot_simplification",
         "//xla/hlo/transforms/simplifiers:broadcast_canonicalizer",