kbuild: use LLVM integrated assembler for C files

Now that all inline assembly can be assembled by LLVM's integrated
assembler, lets use the integreated assembler for c files.

Change-Id: Iad283c150a1553486f23587eb7f925fcadf2839e
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Adam W. Willis <return.of.octobot@gmail.com>
Signed-off-by: Danny Lin <danny@kdrag0n.dev>
(cherry picked from commit 7ac2bc51ab50f8fbcbd04f4fa83950efe819ab8e)
(cherry picked from commit fe683e3cab272795b58bf46f73c8b0260ca6ecc6)
(cherry picked from commit 89d1b03721ddbf8b9abd6ee5a58b77c6fe2f7a34)
(cherry picked from commit ace2eb2dbb024a48f1914b631b687e32f8737669)
(cherry picked from commit 54f2a1d64e29160f3c2427cb5296ca4ba0ab61c7)
Signed-off-by: engstk <eng.stk@sapo.pt>

Makefile

@@ -505,10 +505,9 @@ endif
 ifneq ($(GCC_TOOLCHAIN),)
 CLANG_FLAGS	+= --gcc-toolchain=$(GCC_TOOLCHAIN)
 endif
-CLANG_FLAGS	+= -no-integrated-as
 CLANG_FLAGS	+= -Werror=unknown-warning-option
 KBUILD_CFLAGS	+= $(CLANG_FLAGS)
-KBUILD_AFLAGS	+= $(CLANG_FLAGS)
+KBUILD_AFLAGS	+= $(CLANG_FLAGS) -no-integrated-as
 export CLANG_FLAGS
 endif