wifi: ath11k: remove unused members of 'struct ath11k_base'

Remove set but otherwise unused 'wlan_init_status' and
'wmi_ready' members of 'struct ath11k_base', adjust
'ath11k_wmi_tlv_rdy_parse()' accordingly.

Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230824075121.121144-2-dmantipov@yandex.ru