msm: mdss: Update msm8998 HDMI PHY sequence for bridge chip

Add support for 1.8v external power supply HDMI PHY sequence
which is used by bridge chip.

CRs-Fixed: 1074721
Change-Id: I0ae55cdc9151949b81f6de828238e4b88ceea3df
Signed-off-by: Lei Chen <chenl@codeaurora.org>
Signed-off-by: Yuchao Ma <yuchaom@codeaurora.org>