iwlagn: parsing uart message and take actions

1. Based on uart message from uCode, re-configure BT kill ack mask
messages from uCode
2. send REPLY_BT_COEX_SCO command to uCode based on the uart frame
received from uCode

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>