Detect gscan support in firmware by doing pfn_gscan_cfg iovar with
invalid version.
Reviewed-by: NHante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: NPieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: NFranky Lin <franky.lin@broadcom.com>
Signed-off-by: NArend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: NKalle Valo <kvalo@codeaurora.org>