QCA6174 card often hangs with the current htt_rx_desc
memory layout in some circumstances, because its firmware
fails to handle length differences.
Therefore we must abstract the htt_rx_desc structure
and operations on it, to allow different wireless cards
to use different, unrelated rx descriptor structures.

Define a base htt_rx_desc structure and htt_rx_desc_v1
for use with the QCA family of ath10k supported cards
and htt_rx_desc_v2 for use with the WCN3990 card.

Define htt_rx_desc_ops which contains the abstract operations
to access the generic htt_rx_desc, give implementations
for each card and update htt_rx.c to use the defined
abstract interface to rx descriptors.

Fixes: e3def6f7 ("ath10k: Update rx descriptor for WCN3990 target")

Tested-on: QCA6174 hw3.2 PCI WLAN.RM.4.4.1-00157-QCARMSWPZ-1
Co-developed-by: Enrico Lumetti <enrico@fracta.dev>
Signed-off-by: Enrico Lumetti <enrico@fracta.dev>
Signed-off-by: Francesco Magliocca <franciman12@gmail.com>
Link: https://lore.kernel.org/ath10k/CAH4F6usFu8-A6k5Z7rU9__iENcSC6Zr-NtRhh_aypR74UvN1uQ@mail.gmail.com/Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20211216151823.68878-1-franciman12@gmail.com