ath6kl: add hif_type

In some rare cases core code needs to know what hif type is used. Add
a field to struct ath6kl to denote that. Hopefully this is just a
temporary solution.

Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

diff --cc drivers/net/wireless/ath/ath6kl/core.h
Simple merge

diff --cc drivers/net/wireless/ath/ath6kl/sdio.c
Simple merge