MIPS: BCM47XX: Fix LED inversion for WRT54GSv1

MIPS: BCM47XX: Fix LED inversion for WRT54GSv1

The WLAN LED on the Linksys WRT54GSv1 is active low, but the software
treats it as active high. Fix the inverted logic.

Fixes: 7bb26b169116 ("MIPS: BCM47xx: Fix LEDs on WRT54GS V1.0")
Signed-off-by: Mirko Parthey <mirko.parthey@web.de>
Looks-ok-by: Rafał Miłecki <zajec5@gmail.com>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@linux-mips.org
Cc: <stable@vger.kernel.org> # 3.17+
Patchwork: https://patchwork.linux-mips.org/patch/16071/
Signed-off-by: James Hogan <jhogan@kernel.org>