dt-bindings: phy: ti: phy-gmii-sel: Add bindings for J721e

TI's J721e SoC supports additional PHY modes like QSGMII and SGMII
that are not supported on earlier SoCs. Add a compatible for it.

Extend ti,qsgmii-main-ports property to support selection of upto
two main ports at once across the two QSGMII interfaces.

Signed-off-by: Siddharth Vadapalli <s-vadapalli@ti.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221026074532.109220-2-s-vadapalli@ti.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>