staging: brcm80211: Add bcmchip.h

bcmchip.h contains chip specific core register base address and
address translation macro for core register access. This is
introduced for si/sb utils dependence removal in fullmac driver.

Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>