arm64: add support for reserved memory defined by device tree

Enable reserved memory initialization from device tree.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>

diff --cc arch/arm64/Kconfig
Simple merge

diff --cc arch/arm64/mm/init.c
Simple merge