CFT: bge(4) ASF handling

Hi,

It seems bge(4) had long standing issues on ASF handling. Floris
Bos sent me a patch that fixes ASF issues. While reading bge(4) I
also noticed new handshake method was not enabled on all BCM575X
family of controllers. So if you have ever experienced problems
with ASF or you had to disable ASF in bge(hw.bge.allow_asf) please
test attached patch with ASF and let me know how it goes on your
box.  Note, ASF handling was disabled except HEAD so you may have
to enable it explicitly on your box with hw.bge.allow_asf tunable.

I'm not sure but this would also have effects on bge(4)
suspend/resume issues. So if you have BCM575X or higher controller
and if you have problems with suspend/resume on bge(4) please give
it try.

Thanks.