Default to ARMv7

The current mechanism for determining ARM architecture version
breaks down when cross-compiling. Default to ARMv7 if the user
specifies ARCH=arm. Users wishing to cross-compile for ARMv6
platforms such as the Raspberry Pi should use ARCH=armv6 as
previously required.
Acked-by: Alexander Kartashov <alekskartashov@parallels.com>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>

Makefile

@@ -56,7 +56,7 @@ ifeq ($(ARCH),x86_64)
 endif
 
 ifeq ($(shell echo $(ARCH) | sed -e 's/arm.*/arm/'),arm)
-	ARMV         := $(shell echo $(ARCH) | sed -r -e 's/armv([[:digit:]]).*/\1/')
+	ARMV         := $(shell echo $(ARCH) | sed -nr 's/armv([[:digit:]]).*/\1/p; t; i7')
 	SRCARCH      := arm
 	DEFINES      := -DCONFIG_ARM -DCONFIG_ARMV$(ARMV)