ath10k: turn rawmode into frame_mode

Turn boolean rawmode module param into integer frame_mode param that
contains value from ath10k_hw_txrx_mode enum. As earlier the default
param value is non-RAW (native Wi-Fi) encapsulation. The param name
is selected to be consistent with the similar ath11k param.

This is a preparation step for upcoming encapsulation offloading
support.

Signed-off-by: Sergey Ryazanov <ryazanov.s.a@gmail.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220516032519.29831-4-ryazanov.s.a@gmail.com