phy: qusb: Add support for DP DM pulsing for HS PHY

PMIC on certain targets does not support DP DM pulsing.
This is needed to support detection of HVDCP chargers.
Add support for DP DM pulsing in the HS PHY driver that
PMIC can rely on, to dectect these chargers.

Change-Id: Ib889f57c88658e9d232872ca17270fe8cac2648d
Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>