wifi: Handle world mode country code change

In NL 80211 standard, there is no world mode value definition.
The driver reports country code changed with
NL80211_REGDOM_TYPE_WORLD when CC is world mode.
PS: The general country code type is "NL80211_REGDOM_TYPE_COUNTRY"
with country code value in NL80211_ATTR_REG_ALPHA2.

Solution, query country code when country code is empty.

Bug: 228215022
Test: Manual test
Change-Id: I79e937616101b03dfbab389adf04f2482f79e6a1
1 file changed