xen: move x86/xen/xenpv.c to dev/xen/bus/xenpv.c

[ehem_freebsd_m5p.com]

Summary

Minor changes are necessary to make this processor-independent, but
moving the file out of x86 and into common is the first step (so others
don't add /more/ x86-isms).

Adapted-to-HEAD-by: Elliott Mitchell <[e-mail]>

[royger]

I would consider placing it in sys/dev/xen/bus/xenpv.c

[ehem_freebsd_m5p.com]

Yeah, I've got no idea what-so-ever why one might feel xenpv.c should be
in a "bus" directory. No similarity to any type of bus. No devices
attached at all. Certainly not a bus.

Like so many comments, that one is pretty obvious when suggested.

[royger]

In D29042#650907, @ehem_freebsd_m5p.com wrote:

Yeah, I've got no idea what-so-ever why one might feel xenpv.c should be
in a "bus" directory. No similarity to any type of bus. No devices
attached at all. Certainly not a bus.

I'm confused by the text above, do you agree it should be in a bus/ directory or not?

There are Xen devices (xen timer, xenstore) that attach to the xenpv bus.

[ehem_freebsd_m5p.com]

In D29042#650912, @royger wrote:

I'm confused by the text above, do you agree it should be in a bus/ directory or not?

There are Xen devices (xen timer, xenstore) that attach to the xenpv bus.

My actual view should be reflected in the diff update. I went ahead and moved as requested. Felt like a 20/20 hindsight comment, it does look like a bus since it has devices attached and as such the idea is entirely reasonable.