ARM: dts: msm: Increase dsp cma heap for concurrency on SDM845

Increase dsp heap memory by additional 4MB to support running
sysmon application concurrently with other applications on
remote DSP processor.

Change-Id: I753eb04791dac75f6ad83bccc1d8f1ebb75055ed
Acked-by: Viswanatham Paduchuri <vpaduchu@qti.qualcomm.com>
Signed-off-by: Tharun Kumar Merugu <mtharu@codeaurora.org>