usb: phy-msm-usb: Add floating charger support for new platforms

On new platforms, SMB hardware can perform charger detection and notify
charger type and cable connect status to USB driver. In floating charger
case it will notify floating charger as SDP charger after that usb driver
need to differentiate between SDP and floating charger. Introducing data
contact detection(DCD) here to distinguish between SDP and floated charger.
If DCD detected, it's SDP, otherwise floated charger is detected.

Hence, add support in usb driver to differentiate between SDP changer and
floating charger and also add a debugfs entry to allow users to
enable/disable this.
By default this feature is disabled.

Command to enable floating charger:
    echo "enable" > <debugfs>/msm_otg/floated_charger_enable

dtsi flag to enable flaoting charger:
qcom,floated-charger-enable = <1>

Change-Id: I5a175c067f3c4f08fe7376e331cdf26488344710
Signed-off-by: ChandanaKishori Chiluveru <cchilu@codeaurora.org>
Signed-off-by: Manu Gautam <mgautam@codeaurora.org>