net: phy: phy_device: Call into the PHY driver to set LED offload

net: phy: phy_device: Call into the PHY driver to set LED offload

Linux LEDs can be requested to perform hardware accelerated blinking
to indicate link, RX, TX etc. Pass the rules for blinking to the PHY
driver, if it implements the ops needed to determine if a given
pattern can be offloaded, to offload it, and what the current offload
is. Additionally implement the op needed to get what device the LED is
for.

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Andrew Lunn <andrew@lunn.ch>
Tested-by: Daniel Golle <daniel@makrotopia.org>
Link: https://lore.kernel.org/r/20230808210436.838995-3-andrew@lunn.ch
Signed-off-by: Jakub Kicinski <kuba@kernel.org>