nmk: Use ppc64 for PowerPC 64 bits architecture

This is usual to reference PowerPC 64 bits architectures as 'ppc64',
and let 'powerpc' define PowerPC 32 bits ones.
Acked-by: Cyrill Gorcunov <gorcunov@gmail.com>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Pavel Emelyanov <xemul@virtuozzo.com>

scripts/nmk/scripts/include.mk

@@ -14,7 +14,7 @@ SUBARCH := $(shell uname -m | sed       \
                 -e s/sa110/arm/         \
                 -e s/s390x/s390/        \
                 -e s/parisc64/parisc/   \
-                -e s/ppc.*/powerpc/     \
+                -e s/ppc64.*/ppc64/     \
                 -e s/mips.*/mips/       \
                 -e s/sh[234].*/sh/      \
                 -e s/aarch64.*/arm64/)