mink: fix memory object id overflow

memory object is denoted by 15 bit number i.e. max memory obj id
could be 2^15-1. Once max id has been assigned, id should reset to 0.

Change-Id: I0a4317da8659708d67b73b1327efca64da4cf14f
Signed-off-by: Dinesh K Garg <dineshg@codeaurora.org>