misc: sram: implement reserved sram areas

This implements support for defining reserved areas as subnodes,
to keep the genpool from using these.

Suggested-by: Rob Herring <robherring2@gmail.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Tested-by: Ulrich Prinz <ulrich.prinz@googlemail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --cc drivers/misc/sram.c
Simple merge