qcacmn: Fix regulatory non-offload issues

Current regulatory non-offloads has following issues:
	1) In "iw reg get" output "00" can not be shown when trying to
	   set country code to "00".
	2) In BDF file, if only reg domain is specified then
	   "iw reg get" output should contain alpha2 code of country which
	   first matches with BDF reg domain.

To fix these issues in reg_get_reginfo_form_regdmn_pair(),
populate reg_info->alpha2 with:
	(a) "00" for WORLD domain and
	(b) alpha2 code of first country matching with non WORLD domain.

Change-Id: I5cf87587a1a0f648700cffdc7ff60f05f043f723
CRs-Fixed: 2494516