MIPS: BCM47XX: Add Luxul XAP1500/XWR1750 WiFi LEDs

MIPS: BCM47XX: Add Luxul XAP1500/XWR1750 WiFi LEDs

Some Luxul devices use PCIe connected GPIO LEDs that are not available
until the PCI subsytem and its drivers load. Using the same array for
these LEDs would block registering any LEDs until all GPIOs become
available. This may be undesired behavior as some LEDs should be
available as early as possible (e.g. system status LED). This patch will
allow registering available LEDs while deferring these PCIe GPIO
connected 'extra' LEDs until they become available.

Signed-off-by: Dan Haab <dan.haab@luxul.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Hauke Mehrtens <hauke@hauke-m.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/18952/
Signed-off-by: James Hogan <jhogan@kernel.org>