staging: r8188eu: move SwLedOn and SwLedOff into rtw_led.c

staging: r8188eu: move SwLedOn and SwLedOff into rtw_led.c

Move the low-level functions SwLedOn and SwLedOff from the hal layer
into rtw_led.c. This is the only place where they're used.

There's no need to go through the hal layer for a simple register access
if the driver supports only a single chipset.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20211226195556.159471-3-martin@kaiser.cx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>