Move -Wlogical-op into xcompile

Clang doesn't know `-Wlogical-op`, so let's move it into xcompile where
we can easily distinguish between the two. However, this requires us to
split out `GCC_ADAFLAGS*` from `GCC_CFLAGS*`.

Change-Id: I6a50de0bc5372f61337f237383d32645ba86b0fd
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33579
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/Makefile.inc b/Makefile.inc
index 48879bc9..7ac0a82 100644
--- a/Makefile.inc
+++ b/Makefile.inc
@@ -401,7 +401,7 @@
 
 CFLAGS_common += -pipe -g -nostdinc -std=gnu11
 CFLAGS_common += -nostdlib -Wall -Wundef -Wstrict-prototypes -Wmissing-prototypes
-CFLAGS_common += -Wwrite-strings -Wredundant-decls -Wno-trigraphs -Wlogical-op
+CFLAGS_common += -Wwrite-strings -Wredundant-decls -Wno-trigraphs
 CFLAGS_common += -Wstrict-aliasing -Wshadow -Wdate-time -Wtype-limits
 CFLAGS_common += -fno-common -ffreestanding -fno-builtin -fomit-frame-pointer
 CFLAGS_common += -ffunction-sections -fdata-sections -fno-pie