8960: 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: Ifb715bc2d4bf7fbba78a7201a68ccf3ec93c38b2
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>