ARM: dts: msm: Increasing shared mem region size for sm6150 and atoll

Increase shared memory region for ICP context bank from
100 to 150MB. The extra 50MB is compensated from the I/O
region.

Change-Id: Ib04640e77230dc90ba1b023818aa0141f1c01e58
Signed-off-by: Prakasha Nayak <pnayak@codeaurora.org>