staging: r8188eu: remove LedControlHandler

Export the function that other layers use for setting the led.

Remove the function pointer and the macro to make the led control function
configurable. This driver supports only a single configuration.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20211226195556.159471-15-martin@kaiser.cx


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>