brcmfmac: add chip information to the bus interface

brcmfmac: add chip information to the bus interface

Extend the bus interface with chip identifier and revision. This
will be used when certain devices need special handling in the
driver.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Piotr Haber <phaber@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>