drop the cpu=apple-m4 part as nonessential

Author: martin-frbg

Makefile.arm64

@@ -311,9 +311,9 @@ endif
 ifeq ($(CORE), VORTEXM4)
 ifneq ($(C_COMPILER), GCC)
 ifeq ($(APPLECLANG),1)
-CCOMMON_OPT += -march=armv8.4-a+sme -mcpu=apple-m4
+CCOMMON_OPT += -march=armv8.4-a+sme
 else
-CCOMMON_OPT += -march=armv8.4-a -mcpu=apple-m4
+CCOMMON_OPT += -march=armv8.4-a
 endif
 else
 CCOMMON_OPT += -march=armv8.4-a