usb: renesas_usbhs: disable attch irq after device attached

attch interrupt might happen infinitely on some USB hub (self power?).
This patch disable attch irq after device attached,
and enable it again when detach irq happen.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>