phy: phy-rockchip-inno-usb2: support muxed interrupts

The rk3568 usb2phy has a single muxed interrupt that handles all
interrupts.
Allow the driver to plug in only a single interrupt as necessary.

Signed-off-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Michael Riesch <michael.riesch@wolfvision.net>
Link: https://lore.kernel.org/r/20211215210252.120923-6-pgwipeout@gmail.com


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