nl80211: Pass center frequency in kHz instead of MHz

freq_reg_info expects to get the frequency in kHz. Instead we
accidently pass it in MHz.  Thus, currently the function always
return ERR rule. Fix that.

Fixes: 50f32718 ("nl80211: Add wmm rule attribute to NL80211_CMD_GET_WIPHY dump command")
Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
[fix kHz/MHz in commit message]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>