nl80211: Fix NL80211_CMD_FRAME to not try offchannel without driver support

nl80211: Fix NL80211_CMD_FRAME to not try offchannel without driver support

The offchanok parameter is hardcoded to one in number of paths and that
added NL80211_ATTR_OFFCHANNEL_TX_OK attribute to NL80211_CMD_FRAME
unconditional. cfg80211 rejects this with EINVAL if the driver does not
indicate support for offchannel TX. Fix this by not requesting
offchannel TX depending on driver capabilities. Remain-on-channel
operation was used for those cases anyway, so the additional attribute
was not really needed for these in the first place.

Signed-hostap: Jouni Malinen <jouni@qca.qualcomm.com>