net: phy: Validate PHY LED OPs presence before registering

Validate PHY LED OPs presence before registering and parsing them.
Defining LED nodes for a PHY driver that actually doesn't supports them
is redundant and useless.

It's also the case with Generic PHY driver used and a DT having LEDs
node for the specific PHY.

Skip it and report the error with debug print enabled.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20241008194718.9682-1-ansuelsmth@gmail.com


Signed-off-by: Paolo Abeni <pabeni@redhat.com>