bcma: add support for chipcommon B core

This core is used on BCM4708 to configure the PCIe and USB3 PHYs and it
contains the addresses to the Device Management unit. This will be used
by the PCIe driver first.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>