drm/via: Embed via_dma in via_dri1

Moved the copyright notices so all copyrights are kept.
A few variables was made static as there are no more users outside this
file.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Kevin Brace <kevinbrace@bracecomputerlab.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220713170202.1798216-3-sam@ravnborg.org