ARM: dts: msm: Increase PMIC register dump size on SM8150

The 64 KB dump size that is allocated for the PMIC registers
on SM8150 is not sufficient, and needs to be increased.

Increase PMIC register dump size to 512 KB to allow
dumping of all of the required PMIC registers.

Change-Id: If7c973ceb538c8d4cfee3a4ebe9af332c0113f15
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>