BACKPORT: cfg80211: fix 6 GHz frequencies to kHz

The updates to change to kHz frequencies and the 6 GHz
additions evidently overlapped (or rather, I didn't see
it when applying the latter), so the 6 GHz is broken.
Fix this.

Bug: 163110886

Fixes: 934f4c7dd3a5 ("cfg80211: express channels with a KHz component")
Link: https://lore.kernel.org/r/20200529140425.1bf824f6911b.I4a1174916b8f5965af4366999eb9ffc7a0347470@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Change-Id: If0507c87b898302c091de22f69714eb11eada75b
(cherry picked from commit 5e9cf0f0a3e98992184442de24253fe1b9c40f2e)
Signed-off-by: Vamsi Krishna <vamsin@codeaurora.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>