ath10k: enhance swba event handler to adapt different size tim bitmap

Due to 512 client support in 10.4 firmware, size of tim ie is going
to be slightly higher than non 10.4 firmware. So, size of tim_bitmap
what is carried in swba event from 10.4 firmware is bit higher.

The only bottle neck to reuse existing swba handler
ath10k_wmi_event_host_swba() for 10.4 is that code designed to deal
with fixed size tim bitmap(ie, tim_info[].tim_bitmap in wmi_swba_ev_arg).
This patch removes such size limitation and makes it more suitable
to handle swba event which has different size tim bitmap.

All existing swba event parsing functions are changed to adapt this
change. Actual support to handle 10.4 swba event is added in next patch.
Only preparation is made in this patch.

Signed-off-by: Raja Mani <rmani@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>