ARM: dts: msm: Add common CMA device configuration for msm8909w & apq8909

TZ expects firmware regions under 512MB. BG firmware region is
allocated from common CMA region. Add common CMA configuration
and restrict it within 512MB region for msm8909w and apq8009.

Change-Id: Ifbd10b8af041b397851e983cdb9fc05d17dfe4a3
Signed-off-by: Ramesh Yadav Javadi <javadi@codeaurora.org>