msm: Remove DONT_MAP_HOLE_AFTER_MEMBANK0

The DONT_MAP_HOLE_AFTER_MEMBANK0 feature is now deprecated. Remove
the code associated with it.

Change-Id: I729b9574a7655e97c8e7abc68797b874e90dcac2
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>