dt-bindings: phy: g12a-usb3-pcie-phy: fix compatible string documentation

The compatible string in the driver doesn't have the meson prefix.
Fix this in the documentation and rename the file accordingly.

Fixes: 87a55485

 ("dt-bindings: phy: meson-g12a-usb3-pcie-phy: convert to yaml")
Cc: stable@vger.kernel.org
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/0a82be92-ce85-da34-9d6f-4b33034473e5@gmail.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>