vgaarb: Keep adding VGA device in queue

vgaarb: Keep adding VGA device in queue

BugLink: https://bugs.launchpad.net/bugs/1812797
If failed to find the deivice owning the boot framebuffer,
try to use the first VGA device instead of the last one.

Usually the 1st device is integrated GPU who owns the boot framebuffer.

Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/1535739600-8842-2-git-send-email-aaron.ma@canonical.com
(cherry picked from commit 3d42f1ddc47a69c0ce155f9f30d764c4d689a5fa)
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>