brcmsmac: remove references to PCI

There are no devices which are using bcma and have a PCI bus, just a
PCIe bus or something else. bcma does not support PCI devices, so lets
also remove PCI support from brcmsmac. All devices currently supported
by brcmsmac are PCIe based.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Tested-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>