b44: fix force mac address before ifconfig up

Initializing the b44 MAC & PCI functional blocks in the controller must
occur inside init_one(). This will allow access to the MAC registers.
The controller was being powered up in b44_open() which would not allow
access to the registers before ifconfig was up.
Philip Kohlbecher found this bug.

Signed-off-by: Gary Zambrano <zambrano@broadcom.com>