kbuild: arm: Do not define "comma" twice

The definition of "comma" exists in scripts/Kbuild.include.
We should not double it.
Signed-off-by: NMasahiro Yamada <yamada.m@jp.panasonic.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NMichal Marek <mmarek@suse.cz>

arch/arm/Makefile

@@ -50,8 +50,6 @@ AS		+= -EL
 LD		+= -EL
 endif
 
-comma = ,
-
 # This selects which instruction set is used.
 # Note that GCC does not numerically define an architecture version
 # macro, but instead defines a whole series of macros which makes

arch/arm64/Makefile

@@ -30,8 +30,6 @@ AS		+= -EL
 LD		+= -EL
 endif
 
-comma = ,
-
 CHECKFLAGS	+= -D__aarch64__
 
 # Default value