iwlagn: use bt handler for 2030 and 135 series devices

For bt combo devices, need to use bt enabled handlers and functions

Reported-by: Don Fry <donald.h.fry@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>