ARM: msm: dts: remove active vote from reg-bus on sm8150

This change removes the active vote on register bus.
This change is required with the MMCX separation since
display driver now turns off the MMCX, so bus driver
should not touch any display registers when the cpus
go to idle state.

Change-Id: Ife70c81d8b7df6285121fcb212d637c25eb46b54
Signed-off-by: Abhijit Kulkarni <kabhijit@codeaurora.org>