WMI_PEER_CHAN_WIDTH_SWITCH_CMDID sent from host fragments the
command based on the size of the WMI buffer.
Add support to instead use a FW regulated value taken from the
WMI service ready extended_2 event.
CRs-Fixed: 2684788
Change-Id: Iaeccf785c64b385bf2ad6bc372da239981143fa0