usb: renesas_usbhs: mod_host: add missing .bus_suspend/resume

suspend/resume will failed on renesas_usbhs without this patch.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>