[ARM] Exynos4: Add Odroid support

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

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

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

Signed-off-by: Anup Patel <anup@brainfault.org>
[ARM] Corrected the amount of memory for the odroidx board

Signed-off-by: Anup Patel <anup@brainfault.org>