ath6kl: Support for WLAN Coexistense with LTE

Support for WLAN and LTE to coexist on neighbouring bands
is added.

Signed-off-by: Ram Ranganathan <rrangana@qca.qualcomm.com>
ath6kl: First pass code for IPA support

Support for routing data to/from Wifi through the
IP accelerator (IPA) module is added. With this support
data is routed to/from the AR6004 chip through the IPA.
This enables faster data transfer.

Signed-off-by: Ram Ranganathan <rrangana@qca.qualcomm.com>