phy: msm: usb: Add module param for PHY charger detection

If Data lines are cut off from PMI and PMI still doing charger
detection, then we get an extcon notification from PMI with
charger type as USB_FLOAT. Add a module parameter which if set,
will queue PHY based charger detection to notify actual charger
type and current to PMI.
Usage of the module param 'chg_detection_for_float_charger':
   echo Y > /sys/module/phy_msm_usb/parameters/chg_detection_for_float_charger

Change-Id: Ibdd2e69ea47440d13ca845b0418da9c485e81d2e
Signed-off-by: Ajay Agarwal <ajaya@codeaurora.org>