ARM: dts: msm: update the pasr sizes on bengal

Update the PASR offlineable sizes as below:
6GB DDR --> 1GB offline
8Gb DDR --> 2GB offline

This change is intended to increase the ZONE_NORMAL which can address
the launch latency issues.

Change-Id: I6304826b41e35228791bb935b39ee79a47cf1601