hostap: fix VHT channel center segment0

1) Unless ACS is being used, both "channel" and
"vht_oper_centr_freq_seg0_idx" parameters must be set.
Fixed "channel center segment 0" not being set in VHT Operation IE.
2) Set HT capabilities and VHT capabilities via the wifi ap config command.
3) Set AP bandwidth to wifi driver via the wifi_mgmt_api->ap_config_params.

Signed-off-by: Gang Li <gang.li_1@nxp.com>