Add AP mode support for HT 20/40 co-ex Action frame

Add AP mode support for HT 20/40 co-ex Action frame

If a 2.4 GHz band AP receives a 20/40 Coexistence management frame from
a connected station with 20/40 BSS Intolerant Channel Report element
containing the channel list in which any legacy AP are detected or AP
with 40 MHz intolerant bit set in HT Cap IE is detected in the affected
range of the BSS, the BSS will be moved from 40 to 20 MHz channel width.

Signed-off-by: Jouni Malinen <jouni@qca.qualcomm.com>