phy: rockchip-inno-usb2: Handle bvalid falling

Some SoCs have a bvalid falling interrupt, in addition to bvalid rising.
This interrupt can detect OTG cable plugout immediately, so it can avoid
the delay until the next scheduled work.

Signed-off-by: Samuel Holland <samuel@sholland.org>
Tested-by: Michael Riesch <michael.riesch@wolfvision.net>
Link: https://lore.kernel.org/r/20220414032258.40984-6-samuel@sholland.org


Signed-off-by: Vinod Koul <vkoul@kernel.org>