Remove the ieee80211v option. It previously was required to be enabled
in order to use time_advertisement, time_zone, wnm_sleep_mode and
bss_transition, however it didn't enable any of these options by default.

Remove it, as configuring these options independently is enough.

This change does not influence the behavior of any already configured
setting.

Signed-off-by: David Bauer <mail@david-bauer.net>