usb: dwc3-am62: Enable as a wakeup source by default

USB module can wakeup system. Enable it as a wakeup source
by default. Finer grain wakeup enable/disable can be done
from the power/wakeup system control file of the respective
USB device.

Signed-off-by: Roger Quadros <rogerq@kernel.org>
Acked-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/20230316131226.89540-3-rogerq@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>