check_compliance.py: Add CONFIG_SHIFT to whitelist

Referenced in PR zephyrproject-rtos#13794.

Signed-off-by: Kumar Gala <[email protected]>

Author: galak

scripts/ci/check_compliance.py

@@ -401,6 +401,7 @@ def check_no_undef_outside_kconfig(self, kconf):
     "CONFIG_REG1",
     "CONFIG_REG2",
     "CONFIG_SEL",
+    "CONFIG_SHIFT",
     "CONFIG_SOC_SERIES_",
     "CONFIG_SOC_WATCH",  # Issue 13749
     "CONFIG_SOME_BOOL",