ath: fix world regulatory domain fix-up so that all regulatory rules are processed

r24503 (trunk) and r24505 (backfire) revised the regulatory rules used
for the ath drivers' world regulatory domains in the 5GHz band by
opening up channels 36, 40, 44, and 48 to being used without the
*_PASSIVE_SCAN and *_NO_IBSS flags set. This was done by breaking
ATH9K_5GHZ_5150_5350 into two REG_RULES. The various struct
ieee80211_regdomains that reference these rules in their reg_rules
fields need to have their n_reg_rules fields updated accordingly.

SVN-Revision: 25418