ARM: dts: msm: Move audio heaps over to use reserved CMA regions

Carveout regions are being deprecated. Convert the audio heaps over
to use a reserved CMA region instead of a carveout. At a later time,
the audio regions may be converted over to a fully functional CMA region.

Change-Id: I70d9c671ff118400ee60e669062a7b2092931536
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>