brcmfmac: Change USB probe routine to support Composite USB

Some of the USB devices also have Bluetooth inside. These devices
can with specific firmware result in a composite USB device. This
change will update the driver such that it will also accept the
correct interface of composite devices. It is backward compatible
with old non-composite USB fw.
Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>