msm8974-regulator.dtsi: adjust GFX regulator parameters

settings based on qcom documentation

Signed-off-by: Paul Reioux <reioux@gmail.com>

Conflicts:
	arch/arm/boot/dts/msm8974-regulator.dtsi

Change-Id: Ie0935318f6c122b93e3ce829d3f4076fdf347961
msm8974-regulator.dtsi: further reduce CPU retention voltage

this should help idel drain during processor retention c-state

Signed-off-by: Paul Reioux <reioux@gmail.com>