brcm80211: smac: change from pci device driver to bcma device driver

A new bus driver called "bcma" has been introduced into the kernel tree
which considers the Broadcom AMBA chip interconnect as a bus. Each core in
the chip is a bcma device. This commit changes brcms_mac80211.c into
a bcma device driver.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Alwin Beukers <alwin@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>