drm/atomic: Increase timeout in drm_atomic_helper_wait_for_vblanks()

drm/atomic: Increase timeout in drm_atomic_helper_wait_for_vblanks()

Increase the timeout for vblank events from 100 ms to 1000 ms. This
is the same fix as in commit f050da08a4ed ("drm/vblank: Increase
timeout in drm_wait_one_vblank()") for another vblank timeout.

After merging generic DRM vblank timers [1] and converting several
DRM drivers for virtual hardware, these drivers synchronize their
vblank events to the display refresh rate. This can trigger timeouts
within the DRM framework.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/dri-devel/20250904145806.430568-1-tzimmermann@suse.de/
Reported-by: syzbot+fcede535e7eb57cf5b43@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/dri-devel/69381d6c.050a0220.4004e.0017.GAE@google.com/
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Fixes: 74afeb812850 ("drm/vblank: Add vblank timer")
Link: https://patch.msgid.link/20251209143325.102056-1-tzimmermann@suse.de