drm/mgag200:remove rebundant word "or" in comments

there is a repeated word "or" in comments, so remove it.

Signed-off-by: shaomin Deng <dengshaomin@cdjrlc.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20220718145536.4866-1-dengshaomin@cdjrlc.com