usb: misc: usb3503: Add system sleep support in non-I2C mode

USB3503 chip can be used without any I2C connection, what is handled by
a simple platform device driver. Add support for resetting the chip (via
GPIO lines) during system suspend/resume cycle by adding calls to existing
suspend/resume functions used for E2C device.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>