wireless: only use alpha2 regulatory information from country IE

The meaning and/or usage of the country IE is somewhat poorly defined.
In practice, this means that regulatory rulesets in a country IE are
often incomplete and might be untrustworthy.  This removes the code
associated with interpreting those rulesets while preserving respect
for country "alpha2" codes also contained in the country IE.
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

include/net/regulatory.h

@@ -54,7 +54,6 @@ struct regulatory_request {
 	enum nl80211_reg_initiator initiator;
 	char alpha2[2];
 	bool intersect;
-	u32 country_ie_checksum;
 	enum environment_cap country_ie_env;
 	struct list_head list;
 };