brcm80211: fmac: unify common layer driver data structure

No need to split data structure for common layer into brcmf_pub and
brcmf_info. Absorb brcmf_info into brcmf_pub to increase code
readability.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Reviewed-by: Alwin Beukers <alwin@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>