staging: brcm80211: merged bmac.c into main.c

Future goal is to merge the bmac layer in the driver with the 'common' layer.
A step towards this goal is to have one file containing both bmac and common
code. Header files (bmac.h, main.h) were also merged.

Signed-off-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>