brcmsmac needs bcma. bcma is build into the kernel for the other bcm47xx
subtargets, but not for the legacy target because it only uses ssb. We
could build bcma as a module for bcm47xx_legacy, but none of these old
devices uses a wifi card supported by brcsmac.
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
cb7d662dac