arm: 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>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Git-commit: bcedb5f9bd74662968fc1b4cb22f24abb4b7723d
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>