[nrf fromlist] compliance: Allow phony Kconfigs BAR, FLAG_A and FLAG_B for examples

-This avoids compliance-errors when using the term CONFIG_BAR e.g. in
 API documentation.
-This avoids compliance-errors when using the terms CONFIG_FLAG_A
 and CONFIG_FLAG_B in API documentation.

NOTE: CONFIG_BAR, CONFIG_FLAG_A, and CONFIG_FLAG_B are not real
configurations

Upstream PR #: 87026

Signed-off-by: Frank Audun Kvamtrø <[email protected]>
(cherry picked from commit 7847bf210af5de3b09c0eb40f4cdf30c284ce79a7)

Author: frkv

scripts/ci/check_compliance.py

@@ -946,6 +946,7 @@ def check_no_undef_outside_kconfig(self, kconf):
                               # toolchain Kconfig which is sourced based on
                               # Zephyr toolchain variant and therefore not
                               # visible to compliance.
+        "BAR",
         "BINDESC_", # Used in documentation as a prefix
         "BOARD_", # Used as regex in scripts/utils/board_v1_to_v2.py
         "BOARD_MPS2_AN521_CPUTEST", # Used for board and SoC extension feature tests
@@ -994,6 +995,8 @@ def check_no_undef_outside_kconfig(self, kconf):
         "EXTRA_FIRMWARE_DIR", # Linux, in boards/xtensa/intel_adsp_cavs25/doc
         "FFT",  # Used as an example in cmake/extensions.cmake
         "FLAG",  # Used as an example
+        "FLAG_A", # Used as an example
+        "FLAG_B", # Used as an example
         "FOO",
         "FOO_LOG_LEVEL",
         "FOO_SETTING_1",