cfg80211: add flags to define country IE processing rules

802.11 cards may have different country IE parsing behavioural
preferences and vendors may want to support these. These preferences
were managed by the WIPHY_FLAG_CUSTOM_REGULATORY and the
WIPHY_FLAG_STRICT_REGULATORY flags and their combination.
Instead of using this existing notation, split out the country IE
behavioural preferences to a new flag. This will allow us to add more
customizations easily and make the code more maintainable. Also add
a new flag to disable country IE hints issued by the CORE as the
first customization.

Change-Id: I66ba4a92ac0f029a115eea0a274b02db11279787
CRs-Fixed: 542802
Signed-off-by: Mihir Shete <smihir@codeaurora.org>