VIGS: Refactoring for DRI2

VIGS: Refactoring for DRI2

In order to support DRI2 we must move surfaces from X.Org
into kernel. This implies having additional TTM placement - GPU placement.
We must support eviction in vigs_mman in order to be able to create
surfaces that don't occupy VRAM (Now this is done in X.Org).
Also, command execution must be moved from userland to kernel as well
and we also want to add ability to batch several commands in order
to minimize user-kernel transitions and target-host transitions.

Change-Id: I0a5d3c7627b262c0011c485d8918d125775e9a53