ath9k: Fix BTCOEX weight initialization

The WLAN/BT weights have to set correctly before BTCOEX
is initialized. Currently, this is not done for all chips
in the AR9003 family. This patch fixes this issue by setting
the weights in the init path. While at it, rename ar9462_wlan_weights
to mci_wlan_weights since it is common to both AR9462 and AR9565.

Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>