phy: dt-bindings: Add Cadence D-PHY Rx bindings

The Rx mode DPHY is different from Tx mode DPHY. Add a separate binding
for it.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Rob Herring <robh@kernel.org>

Link: https://lore.kernel.org/r/20220301111621.2992275-5-p.yadav@ti.com


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