wil6210: add FT roam support for AP and station

This feature is needed for enterprise APs and clients to enable
fast roaming as defined in 802.11r between APs in the same ESS.

On AP side, this feature is supported only when disable_ap_sme
is enabled.

Signed-off-by: Ahmad Masri <amasri@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>