arm: Set XEN_COMPILE_ARCH correctly from "uname -m" on ARM

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Committed-by: Ian Campbell <Ian.Campbell@citrix.com>

Config.mk

@@ -13,7 +13,7 @@ realpath = $(wildcard $(foreach file,$(1),$(shell cd -P $(dir $(file)) && echo "
 debug ?= y
 
 XEN_COMPILE_ARCH    ?= $(shell uname -m | sed -e s/i.86/x86_32/ \
-                         -e s/i86pc/x86_32/ -e s/amd64/x86_64/)
+                         -e s/i86pc/x86_32/ -e s/amd64/x86_64/ -e s/arm.*/arm/)
 XEN_TARGET_ARCH     ?= $(XEN_COMPILE_ARCH)
 XEN_OS              ?= $(shell uname -s)