Revert "mac80211_hwsim: VHT add 160MHz width support"

This reverts commit c17aa52c.

It was wrong, IEEE80211_VHT_CAP_SUPP_CHAN_WIDTH_160_80PLUS80MHZ
already implies that 160 MHz is supported, as it isn't a bitmap
but rather a value in a 2-bit field.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>