brcmfmac: move firmware related structures to fwil_types.h

The firmware control interface is provided by fwil source file, but
a number of structures used to communicate with the firmware still
resided in dhd.h. The patch moves them to fwil_types.h.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>