msm: USB: Add support for USB ID detection

For USB Host mode, ID detection for USB connect and disconnect is
done using PMIC or PHY based on the platforms supporting PMIC or PHY
based ID detection. For PMIC and PHY based ID detection, support is
already added in driver.
For platform like MSM8916 where ID line is neither routed to PMIC nor
PHY, hence PMIC and PHY cannot be used for USB ID detection on these
platforms.
This change enables support for USB ID detection using external ID line
connected to msm gpio.

CRs-fixed: 601057
Change-Id: If8a585002145df4175441008bae7681774587e24
Signed-off-by: Saket Saurabh <ssaurabh@codeaurora.org>