toolchain/gcc: Fix GCC version check

The version check which sets GCC_VERSION_FILE to the correct value only
worked when the advanced options menu was active and not when it was not
active.

Thank you Tony Butler for the fix.

Signed-off-by: Hauke Mehrtens <[email protected]>

toolchain/gcc/common.mk

@@ -178,7 +178,7 @@ define Host/SetToolchainInfo
 endef
 
 
-ifdef CONFIG_GCC_USE_VERSION_12
+ifeq ($(GCC_MAJOR_VERSION),12)
 	GCC_VERSION_FILE:=gcc/genversion.cc
 else
 	GCC_VERSION_FILE:=gcc/version.c