cfg80211: Fix parsed country IE info for 5 GHz

cfg80211: Fix parsed country IE info for 5 GHz

The country IE number of channels on 5 GHz specifies the number
of 5 GHz channels, not the number of sequential channel numbers.
For example, if in a country IEs if the first channel given is 36
and the number of channels passed is 4 then the individual channel
numbers defined for the 5 GHz PHY by these parameters

are: 36, 40, 44, 48
not: 36, 37, 38, 39

See: http://tinyurl.com/11d-clarification

Signed-off-by: Luis R. Rodriguez <[email protected]>
Acked-by: Johannes Berg <[email protected]>
Signed-off-by: John W. Linville <[email protected]>