dt-bindings: phy: rockchip-emmc-phy: Convert to dtschema

Convert txt bindings of Rockchip EMMC PHY to dtschema to allow
for validation.

Signed-off-by: Shresth Prasad <shresthprasad7@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240620212806.3011-2-shresthprasad7@gmail.com


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