[PATCH] bcm43xx-softmac: Fix system hang for x86-64 with >1GB RAM

The bcm43xx-softmac software currently fails when running on x86_64 systems
with more than 1GB RAM and one of the card variants with 30-bit DMA addressing.
This patch uses the address extension bits in the hardware to set the correct
DMA mask for the specific card in use.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>