phy: ti: j721e-wiz: Don't configure wiz if its already configured

Serdes lanes might be shared between multiple cores in some usecases
and its not possible to lock PLLs for both the lanes independently
by the two cores. This requires a bootloader to configure both the
lanes at early boot time.

To handle this case, skip all configuration if any of the lanes has
already been enabled.

While we are here, also fix the wiz_init() to be called before the
of_platform_device_create() call.

Signed-off-by: Faiz Abbas <faiz_abbas@ti.com>