Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

This forms the basis for the new APIs that will be exposed to userspace,
giving it access to:

- Object method calls, the immediately useful of which is performance
  counters and the abiity to manipulate the ZBC tables.
- Information on the child classes an object supports, in order to avoid
  having to try all supported classes until successful.
- Notifications, which will be used in the future to inform the client
  if its channel was killed due to a lockup, etc.

This commit imports the interfaces, but are not currently used.  The DRM
portion of the driver will be ported to speak to the core using these
interfaces as much as possible.
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>

This is a lot of prep-work for being able to send event notifications
back to userspace.  Events now contain data, rather than a "something
just happened" signal.

Handler data is now embedded into a containing structure, rather than
being kmalloc()'d, and can optionally have the notify routine handled
in a workqueue.

Various races between suspend/unload with display HPD/DP IRQ handlers
automagically solved as a result.
Signed-off-by: NBen Skeggs <bskeggs@redhat.com>