Reworking of GPU reset logic + dumping

[j.glisse at gmail.com]

Patches also available at:
http://people.freedesktop.org/~glisse/debug/

So it's the Christian series minus all the debugfs related to
ring/ib/mc. The last patch add a new blob dumping facilities
that dump everythings (pm4, relocs table, bo content). It's
just a proof of concept to show what i meant because code
speaks more clearly on this kind of topic.

The blob format we dump could be different i want with a
simple binary dword format:
type, id, size, [data (present if size > 0)]

Note that the benefit (simpler code, less code) of dumping
current debugfs seems to me greater than their usefullness.

Cheers,
Jerome