[ARM] Exynos4: Add Vexpress-A9 as guest.

Signed-off-by: Anup Patel <anup@brainfault.org>
[ARM] Exynos4: move Guest NOR flash size to 16 MB.

Signed-off-by: Anup Patel <anup@brainfault.org>
[ARM] Exynos4: Fix the reset code.

This does not seems to be supported by Qemu. Therefore it is not
tested.

Signed-off-by: Anup Patel <anup@brainfault.org>
[ARM] Exynos4: fix MCT implementation related to the input clock rate.

Signed-off-by: Anup Patel <anup@brainfault.org>
[DOCS] Exynos4: Add documentation.

Signed-off-by: Anup Patel <anup@brainfault.org>
Merge remote-tracking branch 'upstream/master' into dev_exynos4
[DOCS] Exynos4: fix duplicate in HOSTS file.

Signed-off-by: Jean-Christophe DUBOIS <jcd@tribudubois.net>