dt-bindings: phy: ti: phy-gmii-sel: Cleanup example

Change node name in example from "phy-gmii-sel" to "phy", following the
device-tree convention of using generic node names.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220912085650.83263-2-s-vadapalli@ti.com


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