drivers: of: add initialization code for dynamic reserved memory

drivers: of: add initialization code for dynamic reserved memory

This patch adds support for dynamically allocated reserved memory regions
declared in device tree. Such regions are defined by 'size', 'alignment'
and 'alloc-ranges' properties.

Based on previous code provided by Josh Cartwright <joshc@codeaurora.org>

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Grant Likely <grant.likely@linaro.org>
(cherry picked from commit 3f0c8206644836e4f10a6b9fc47cda6a9a372f9b)
Signed-off-by: Mark Brown <broonie@linaro.org>