MIPS support to *.mk files and envsetup.sh

Change-Id: Iba4d046e3202524b29cfe32980927f8cc0aa8496
Signed-off-by: Chris Dearman <chris@mips.com>
Signed-off-by: Raghu Gandham <raghu@mips.com>
diff --git a/target/board/generic/BoardConfig.mk b/target/board/generic/BoardConfig.mk
index cee09ce..233b136 100644
--- a/target/board/generic/BoardConfig.mk
+++ b/target/board/generic/BoardConfig.mk
@@ -6,6 +6,7 @@
 # The generic product target doesn't have any hardware-specific pieces.
 TARGET_NO_BOOTLOADER := true
 TARGET_NO_KERNEL := true
+TARGET_ARCH := arm
 
 # Note: we build the platform images for ARMv7-A _without_ NEON.
 #