BL30: Reduce the voltage of gpu in standby mode [1/3]

PD#IPTV-26389

Problem:
Need to reduce the voltage of gpu to 0.8V in standby

Solution:
Add related logic

Verify:
S5 pass

Change-Id: I23bb786c1d29f75758852a9e4d8acf681aac9f17
Signed-off-by: binbin.wang <binbin.wang@amlogic.com>
1 file changed