brcmfmac: move configuration of probe request IEs

The configuration of the IEs for probe requests was done in a P2P
related function, which is not very obvious. Moving it to
.scan callback function, ie. brcmf_cfg80211_scan().

Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>