msm: clock-8084: Add HDMI clock support

HDMI clocks have sources coming from the outside of the MMSS clock
controller. Add the support for them and hook them into display clock
controller.

Change-Id: I85d139ecf5d930aa543623987ae5b414fdc051fb
Signed-off-by: Tianyi Gou <tgou@codeaurora.org>