armv7: Add emulation/qemu-armv7 board.

To simplify testing ARM implementation, we need a QEMU configuration for
ARM. The qemu-armv7 provides serial output, CBFS simulation, and full
boot path (bootblock, romstage, ramstage) to verify the boot loader
functionality.

To run with QEMU:
 export QEMU_AUDIO_DRV=none
 qemu-system-arm -M vexpress-a9 -m 1024M -nographic -kernel build/coreboot.rom

Verified to boot until ramstage loaded successfully by QEMU v1.0.50.

Change-Id: I1f23ffaf408199811a0756236821c7e0f2a85004
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-on: http://review.coreboot.org/2354
Reviewed-by: David Hendricks <dhendrix@chromium.org>
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
diff --git a/src/cpu/armltd/Makefile.inc b/src/cpu/armltd/Makefile.inc
new file mode 100644
index 0000000..014742f
--- /dev/null
+++ b/src/cpu/armltd/Makefile.inc
@@ -0,0 +1 @@
+subdirs-$(CONFIG_CPU_ARMLTD_CORTEX_A9) += cortex-a9