adsprpc: Map dynamic loading memory persistent

Add a structure variable to identify persistent map
of cma buffer for dynamic loading on Audio PD
and map persistent.Thus, decreasing the chance
for defragmentation within the cma region.

Change-Id: I1741677bf3c994e7c57223d0543179dbf43d5ca8
Signed-off-by: Jeya R <jeyr@codeaurora.org>