wlcore: add wl1285 compatible

Motorola Droid 4 uses a WL 1285C. With differences between
chips not being public let's add explicit binding for wl1285
instead of relying on wl1283 being very similar.

Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>