ARM: dts: msm: Update device tree with memory map information for 8974

Update the device tree in order to be aligned with the latest memory
map. As the venus and adsp images are relocatable, reclaim the memory
that was previously occupied by non relocatable images of these
subsystems.

Change-Id: I4c4ff452f01877378247d275a9a86ee88a1948cb
Signed-off-by: Neeti Desai <neetid@codeaurora.org>