qcom-charger: Allow PD for hvdcp

Currently the code prevents pd if an hvdcp is detected. We want to
change that in that we want to prevent pd only while hvdcp detection
is in progress.  Once completed, we need to enable pd even if an  hvdcp
is detected. Enabling PD even for hvdcp allows us to detect a QC 4.0
which communicates over PD.

Currently we model the pd_allowed votable as an enable votable i.e.
if any one of the voters enable it, pd_allowed gets enabled.

Change that to a disable votable named pd_disallowed_votable,
which gets disabled when CC is detached, and hvdcp2.0 detection is not
yet completed.

Change-Id: I2ae261c71694695b41d8a31c4b40542d5e227c3a
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>