qcacmn: Populate the correct opclass for 6G channels

For the 6G band, the only valid opclass_table is the global_op_class
as per the current specification. Therefore, if the band is 6G set the
opclass to global_op_class instead of the default us_op_class.

As per specification for chan width 40 MHz, there is no behav limit
for both Low Primary and High Primary channels. Hence, set behav limit
as BIT(BEHAV_NONE) if channel width is 40 MHz.

Change-Id: I534f5b898e10cf21042a117aa71e824a85d73fb3
CRs-Fixed: 2608059