arm64: lse: Pass -fomit-frame-pointer to out-of-line ll/sc atomics

In cases where x30 is used as a temporary in the out-of-line ll/sc atomics
(e.g. atomic_fetch_add), the compiler tends to put out a full stackframe,
which included pointing the x29 at the new frame.

Since these things aren't traceable anyway, we can pass -fomit-frame-pointer
to reduce the work when spilling. Since this is incompatible with -pg, we
also remove that from the CFLAGS for this file.

Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm64/lib/Makefile

@@ -17,6 +17,7 @@ CFLAGS_atomic_ll_sc.o	:= -fcall-used-x0 -ffixed-x1 -ffixed-x2		\
 		   -ffixed-x7 -fcall-saved-x8 -fcall-saved-x9		\
 		   -fcall-saved-x10 -fcall-saved-x11 -fcall-saved-x12	\
 		   -fcall-saved-x13 -fcall-saved-x14 -fcall-saved-x15	\
-		   -fcall-saved-x18
+		   -fcall-saved-x18 -fomit-frame-pointer
+CFLAGS_REMOVE_atomic_ll_sc.o := -pg
 
 lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o