usb: dwc3: Drive a pulse on DP on CDP detection

Some USB host PCs switch the downstream port mode from
CDP to SDP if the device does not pull DP up within certain
duration (~2s).
This limits the current drawn by the device to 500mA(or 900mA)
as opposed to the possible 1.5A resulting in slow charging of
the battery.
Fix this by driving a DP pulse when there is a connect
notification from PMIC and detected the charger type as CDP.

The ser current call also leads to the same failure, hence
limit the set current call only to the case where the device
is connected to a Standard Downstream Port.

Change-Id: I2c737c68de57bc4126fb3e6e1c291b83d681fb13
Signed-off-by: Sriharsha Allenki <sallenki@codeaurora.org>