b43: Add missing MODULE_FIRMWARE()

Some firmware entries were forgotten to be added via MODULE_FIRMWARE(), which
may result in the non-functional state when the driver is loaded in initrd.

Link: http://bugzilla.opensuse.org/show_bug.cgi?id=1037344
Fixes: 15be8e89

 ("b43: add more bcma cores")
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>