wifi: ath11k: refactor ath11k_wmi_tlv_parse_alloc()

Since 'ath11k_wmi_tlv_parse_alloc()' always operates on
'skb->data, skb->len' tuple, it may be simplified to pass
the only 'skb' argument instead (which also implies
refactoring of 'ath11k_pull_bcn_tx_status_ev()' and
'ath11k_pull_chan_info_ev()' in the same way). Compile
tested only.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20231214161117.75145-1-dmantipov@yandex.ru