msm_fb: HDMI: Update HPD logic to address HDMI PLL related issues

In the current implementation, the regulators pertaining to the
HDMI core are turned off/on as part of the configuration of the
HDP circuitry. As a result, the regulator that powers the HDMI
PLL is turned off before the HDMI clocks on the PLL are disabled.
This might lead to the PLL not getting locked when it is re-enabled.

This change turns on and off the regulators and clocks in proper
sequence.

CRs-Fixed: 360135
CRs-Fixed: 358598
Change-Id: Ie3630b543e78e83dc565edc32239935135ca4ca5
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>