staging: brcm80211: remove definition of BCMFASTPATH macro

The macro was used to assure function flagged with this macro were
placed in a named section. However, in the linux build enviroment
there is no such section specified in the linker scripts so it makes
no sense to keep it in.

Cc: devel@linuxdriverproject.org
Reviewed-by: Henry Ptasinski <henryp@broadcom.com>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Brett Rudley <brudley@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>