net: wireless: bcmdhd: Remove "dhd_handle_swc_evt" from dhd.

Remove SWC(siginificant wifi change) from the host. Since current
feature is no longer being used. If needed will get the feature
back. Due to this there will not any heap overflow in
"dhd_handle_swc_evt" will be observed.

Signed-off-by: Sudhir Kohalli <sudhir.kohalli@broadcom.com>
Bug: 37685267
Change-Id: Ib03a39626223e27079f2b3f91564eb21025e57cf