cfg80211: Add support for 60GHz band channels 5 and 6

The current support in the 60GHz band is for channels 1-4.
Add support for channels 5 and 6.
This requires enlarging ieee80211_channel.center_freq from u16 to u32.

Signed-off-by: Alexei Avshalom Lazar <ailizaro@codeaurora.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Git-commit: 9cf0a0b4b64ae103cf0e7dfaa72b44ecda24c0eb
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next.git


CRs-Fixed: 2743684
Change-Id: I8e38c2e97d1f1e8f8f3e21e91a6a70f335a8447a
Signed-off-by: Vinita S. Maloo <vmaloo@codeaurora.org>