b43legacy: fix initvals loading on bcm4303

This allows for the correct initial values to be uploaded to bcm4303
devices. It should be correct, but I can't reliably test this as I suspect
there's something going wrong with an hardware rfkill switch on my laptop.
Please test.

Signed-off-by: Stefano Brivio <stefano.brivio@polimi.it>
Signed-off-by: John W. Linville <linville@tuxdriver.com>