xserver-xorg: upgrade 21.1.15 -> 21.1.16

xserver-xorg: upgrade 21.1.15 -> 21.1.16

Includes security fix

  * CVE-2025-26594
  * CVE-2025-26595
  * CVE-2025-26596
  * CVE-2025-26597
  * CVE-2025-26598
  * CVE-2025-26599
  * CVE-2025-26600
  * CVE-2025-26601

Ref: https://lists.x.org/archives/xorg-announce/2025-February/003584.html
     https://lists.x.org/archives/xorg-announce/2025-February/003585.html

Signed-off-by: Vijay Anusuri <vanusuri@mvista.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit b5491688a045e52b2a1a00d04b746ed6af456784)
Signed-off-by: Steve Sakoman <steve@sakoman.com>