bcma: scan for extra address space

Some cores like the USB core have two address spaces. In the USB host
controller one address space is used for the OHCI and the other for the
EHCI controller interface. The USB controller is the only core I found
with two address spaces. This code is based on the AI scan function
ai_scan() in shared/aiutils.c in the Broadcom SDK.

CC: Rafał Miłecki <zajec5@gmail.com>
CC: linux-wireless@vger.kernel.org
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>