ARM: dts: msm: Increase CMA memory for SM8150

WLAN QCA6390 device requires more than 10MB contiguous memory
in total. Currently CMA region only has 32MB which will be used
across multiple drivers and it's not enough anymore. Increase it
to 40MB in order to fulfill new memory requirement.

Change-Id: I128d7238cf37726ea2ef9cdf2cf8d6da2f5a16e6
Signed-off-by: Yue Ma <yuem@codeaurora.org>