staging: r8188eu: merge rtw_led_control and SwLedControlMode1

rtw_led_control is the only caller of SwLedControlMode1.
Pull SwLedControlMode1 into rtw_led_control.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20211226195556.159471-21-martin@kaiser.cx


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