drm/vkms: Add extra information about vkms

Add the following additional information: authors and description in
Kconfig.

Signed-off-by: Rodrigo Siqueira <rodrigosiqueiramelo@gmail.com>
Reviewed-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/180770375b0537f1ba1857bdb7fdc71dd201882e.1526514457.git.rodrigosiqueiramelo@gmail.com