phy: ti: phy-j721e-wiz: stop name conflict if multiple serdes are initialized

When multiple serdes instances are initialized the first will succeed but
additional will conflict over clocks names and probing fails.

Signed-off-by: Matt Ranostay <mranostay@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>