MLK-11272 usb: chipidea: otg: data pulse detection work around for imx7d

i.MX7D has a silicon issue on full speed termination after A device ends
a session, which causes it can not detect data pulse from B device if
A device isn't in low power mode, this patch work around it by override
Termsel bit to be 1 for FS mode termination. After A device detects data
pulse or turns on vbus, this override will be cleared and disabled.

Signed-off-by: Li Jun <jun.li@freescale.com>