usb: chipidea: introduce imx7d USB charger detection

imx7d (and imx8mm, imx8mn) uses Samsung PHY and USB generic PHY driver.
The USB generic PHY driver is impossible to have a charger detection
for every user, so we implement USB charger detection routine at glue
layer. After the detection has finished, it will notify USB PHY
charger framework, and the uevents will be triggered.

Signed-off-by: Jun Li <jun.li@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>