doc: posix: options: mark _POSIX_THREAD_SAFE_FUNCTIONS supported

Mark the _POSIX_THREAD_SAFE_FUNCTIONS Option as supported.

This Option is required mandatory for any conformant
implementation and is comprised of functions belonging to the
following Option Groups:

- POSIX_C_LANG_SUPPORT_R
- POSIX_FILE_LOCKING
- POSIX_FILE_SYSTEM_R
- POSIX_SYSTEM_DATABASE_R

Signed-off-by: Chris Friedt <cfriedt@tenstorrent.com>

doc/services/portability/posix/option_groups/index.rst

@@ -1031,27 +1031,29 @@ Enable this option with :kconfig:option:`CONFIG_POSIX_THREAD_PRIORITY_SCHEDULING
 _POSIX_THREAD_SAFE_FUNCTIONS
 ++++++++++++++++++++++++++++
 
-Enable this option with :kconfig:option:`CONFIG_POSIX_THREAD_SAFE_FUNCTIONS`.
+Enable this option with :kconfig:option:`CONFIG_POSIX_C_LANG_SUPPORT_R`,
+:kconfig:option:`CONFIG_POSIX_FILE_LOCKING`, :kconfig:option:`CONFIG_POSIX_FILE_SYSTEM_R`,
+and :kconfig:option:`CONFIG_POSIX_SYSTEM_DATABASE_R`.
 
 .. csv-table:: _POSIX_THREAD_SAFE_FUNCTIONS
     :header: API, Supported
     :widths: 50,10
 
     asctime_r(), yes
     ctime_r(), yes (UTC timezone only)
-    flockfile(),
-    ftrylockfile(),
-    funlockfile(),
-    getc_unlocked(),
-    getchar_unlocked(),
-    getgrgid_r(),yes :ref:`†<posix_undefined_behaviour>`
-    getgrnam_r(),yes :ref:`†<posix_undefined_behaviour>`
-    getpwnam_r(),yes :ref:`†<posix_undefined_behaviour>`
-    getpwuid_r(),yes :ref:`†<posix_undefined_behaviour>`
+    flockfile(), yes
+    ftrylockfile(), yes
+    funlockfile(), yes
+    getc_unlocked(), yes
+    getchar_unlocked(), yes
+    getgrgid_r(),yes
+    getgrnam_r(),yes
+    getpwnam_r(),yes
+    getpwuid_r(),yes
     gmtime_r(), yes
     localtime_r(), yes (UTC timezone only)
-    putc_unlocked(),
-    putchar_unlocked(),
+    putc_unlocked(), yes
+    putchar_unlocked(), yes
     rand_r(), yes
     readdir_r(), yes
     strerror_r(), yes