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>

src/mainboard/emulation/qemu-armv7/timer.c

@@ -0,0 +1,24 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2013 Google, Inc.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+void udelay(unsigned int n);
+void udelay(unsigned int n) {
+	/* TODO provide delay here. */
+}
+
+int init_timer(void);
+int init_timer(void) {
+	return 0;
+}