wifi: ath10k: add missing wmi_10_4_feature_mask documentation

Currently kernel-doc reports the following issues:
drivers/net/wireless/ath/ath10k/wmi.h:3033: warning: Enum value 'WMI_10_4_EXT_PEER_TID_CONFIGS_SUPPORT' not described in enum 'wmi_10_4_feature_mask'
drivers/net/wireless/ath/ath10k/wmi.h:3033: warning: Enum value 'WMI_10_4_REPORT_AIRTIME' not described in enum 'wmi_10_4_feature_mask'

Update the kernel-doc for enum wmi_10_4_feature_mask to add the
missing documentation.

No functional changes, compile tested only.

Signed-off-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://msgid.link/20240118-ath10k-kerneldoc-v1-1-99c7e8d95aad@quicinc.com