When USE_ASHMEM is set, ASHMEM will be used only for non-MDP composition.
This implementation will force to use PMEM for MDP composition case. This
will allow using ASHMEM or PMEM at run time, depending on the composition
type. USE_ASHMEM would mean that use ASHMEM where possible.
This will also make sure that video works properly when dynamic ASHMEM
feature is enabled on 7x27 / 7x27a / 7x25a targets.
Change-Id: I5860311aad20d33e2d078cd6f0d05e041ff3364a