usb: cdns3: drd: changed return type from int to bool

Patch changes return type from int to bool for
cdns3_is_host and cdns3_is_device functions.

Reviewed-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>