wireless: add check of field VHT Extended NSS BW Capable for 160/80+80 MHz setting

wireless: add check of field VHT Extended NSS BW Capable for 160/80+80 MHz setting

Table 9-251—Supported VHT-MCS and NSS Set subfields, it has subfield VHT Extended
NSS BW Capable, its definition is:
Indicates whether the STA is capable of interpreting the Extended NSS BW
Support subfield of the VHT Capabilities Information field.

This patch is to add check for the subfield.

Signed-off-by: Wen Gong <wgong@codeaurora.org>
Link: https://lore.kernel.org/r/20210524033624.16993-1-wgong@codeaurora.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>