Channel switching issue in AP mode

[darkdarkgray]

sigma-dut/ap.c

Line 12855 in d2b559b

" -i %s chan_switch 10 %d sec_channel_offset=1 center_freq1=%d bandwidth=%d blocktx vht",

Hostapd failed when we try to switch channel with sigma_dut in AP mode and bandwidth 80MHz and more.
Because of hardcoded "sec_channel_offset=1" we can switch only to half of channels list. (36 - ok, 40 - failed, 44 - ok, 48 - failed, etc).
To fix that we need to calculate sec_channel_offset according to channel frequency, center_freq1 and bandwidth.