p54: more SoftLED updates

This patch hopefully finishes the SoftLED code:
- It adds two more LEDs (rx and radio).
  (the FW claims it can support up to 16 LEDs,
   but I doubt that any vendor put more than 4 on a board)
- update the LEDs in a _delayed_ workqueue.
  No one reported any more crashes.
  (see: "PATCH] p54: fix race condition in memory management")
  So we can stop burning the mm code.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>