check_compliance.py: Add STACK_SIZE to Kconfig symbol whitelist

Needed for zephyrproject-rtos/zephyr#20722.

Signed-off-by: Ulf Magnusson <[email protected]>

Author: ulfalizer

scripts/check_compliance.py

@@ -486,6 +486,7 @@ def check_no_undef_outside_kconfig(self, kconf):
     "SOME_INT",
     "SOME_OTHER_BOOL",
     "SOME_STRING",
+    "STACK_SIZE",  # Used as an example in the Kconfig docs
     "STD_CPP",  # Referenced in CMake comment
     "TEST1",
     "TYPE_BOOLEAN",