arm64: dts: ti: k3-j721e-common-proc-board: Re-name "link" name as "phy"

Commit 66db854b ("arm64: dts: ti: k3-j721e-common-proc-board:
Configure the PCIe instances") and
commit 02c35dca ("arm64: dts: ti: k3-j721e: Enable Super-Speed
support for USB0") added PHY DT nodes with node name as "link"
However nodes with #phy-cells should be named 'phy' as discussed in [1].
Re-name subnodes of serdes in J721E to 'phy'.

[1] -> http://lore.kernel.org/r/20200909203631.GA3026331@bogus



Fixes: 66db854b ("arm64: dts: ti: k3-j721e-common-proc-board: Configure the PCIe instances")
Fixes: 02c35dca ("arm64: dts: ti: k3-j721e: Enable Super-Speed support for USB0")
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Reviewed-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20210603143427.28735-5-kishon@ti.com