Revert "igc: Export LEDs"

This reverts commit cf833182

.

There are better Linux interfaces to export the different LED modes
and blinking reasons.

Revert this patch for now and come up with better solution later.

Suggested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Kurt Kanzenbach <kurt@linutronix.de>
Link: https://lore.kernel.org/r/20210719101640.16047-1-kurt@linutronix.de


Signed-off-by: Jakub Kicinski <kuba@kernel.org>