ARM: dts: msm: increase modem size as per new memory map

Increase modem size from 139MB to 147MB on 512MB variant
as per new memory map for CV2X support for sdxpoorwills
adp board.

Change-Id: I37d1068dfc1fd36755f0910f53148e515d5741c8
Signed-off-by: Abinaya P <abinayap@codeaurora.org>