[wlan][mlme][test] Augment Mock BSS

CreateBSSDescription() takes wlan_channel_t.
CreateAssociateResponse() takes HT cap, HT op, VHT cap, VHT op
for construction.

Test: This is test code. Ran wlan unit testers.
NET-1923
NET-2007

Change-Id: Idc02dad06b83aab8dd8511fde061fcc4d694f77c
2 files changed