drm/vmwgfx: Cleanup logging

The code was using the old DRM logging functions, which made it
hard to figure out what was coming from vmwgfx. The newer logging
helpers include the driver name in the logs and make it explicit
which driver they're coming from. This allows us to standardize
our logging a bit and clean it up in the process.

vmwgfx is a little special because technically the hardware it's
running on can be anything from the last 12 years or so which is
why we need to include capabilities in the logs in the first
place or otherwise we'd have no way of knowing what were
the capabilities of the platform the guest was running in.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210723165153.113198-2-zackr@vmware.com