usb: chipidea: Fix otg event handler

[ Upstream commit 59739131e0ca06db7560f9073fff2fb83f6bc2a5 ]

At OTG work running time, it's possible that several events need to be
addressed (e.g. ID and VBUS events). The current implementation handles
only one event at a time which leads to ignoring the other one. Fix it.

Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>