usb: phy: snps: Adding support for CDP detection with synopsis PHY

Commit 24275f467345 ("usb: dwc3: Drive a pulse on DP on CDP detection")
drives a DP pulse when there is connect notification from PMIC to
ensure that host does not change CDP to SDP. However, synopsis PHY
had no such support for CDP detection.
Fix this by adding support for CDP detection is synopsis PHY.

Change-Id: Ie5ad53928a9c1cf2a16575ad3781bceaf1dd1f9a
Signed-off-by: Udipto Goswami <ugoswami@codeaurora.org>