wil6210: sync with the latest FW API

- add pcp_max_assoc_sta to the struct wmi_pcp_start_cmd
- enum for the scan ststus

Signed-off-by: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>