phy: phy-can-transceiver: Add support for setting mux

On some boards, for routing CAN signals from controller to transceiver,
muxes might need to be set. Therefore, add support for setting the mux by
reading the mux-states property from the device tree node.

Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Link: https://lore.kernel.org/r/20220408111316.21189-1-a-govindraju@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>