8930: Add support for using CMA with ion heaps

Adjust the memory reservation/placing code in the board
file to account for heaps that might use CMA. This includes
both dedicated CMA heaps and cp heaps marked as using CMA.

Change-Id: I71a96e93a974d9a1adcbc4b9d0dc172740f7f299
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>