sh: Fix up uname -m matching for native sh64.

Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

Makefile

@@ -169,7 +169,7 @@ SUBARCH := $(shell uname -m | sed -e s/i.86/i386/ -e s/sun4u/sparc64/ \
 				  -e s/arm.*/arm/ -e s/sa110/arm/ \
 				  -e s/s390x/s390/ -e s/parisc64/parisc/ \
 				  -e s/ppc.*/powerpc/ -e s/mips.*/mips/ \
-				  -e s/sh[234].*/sh/ )
+				  -e s/sh.*/sh/ )
 
 # Cross compiling and selecting different set of gcc/bin-utils
 # ---------------------------------------------------------------------------