CI: Use more specific Xilinx runner tags

In order to avoid serialising the testing on both boards, the runner
configuration is being adjusted.

Have the .xilinx-arm64 and .xilinx-x86_64 templates choose the board directly
using a more specific tag.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Victor Lira <victorm.lira@amd.com>
Release-Acked-by: Oleksii Kurochko <oleksii.kurochko@gmail.com>

automation/gitlab-ci/test.yaml

@@ -119,7 +119,7 @@
           && $CI_COMMIT_REF_PROTECTED == "true"
       when: on_success
   tags:
-    - xilinx
+    - xilinx-zynq-423
 
 .xilinx-x86_64:
   extends: .test-jobs-common
@@ -139,7 +139,7 @@
           && $CI_COMMIT_REF_PROTECTED == "true"
       when: on_success
   tags:
-    - xilinx
+    - xilinx-crater-001
 
 .adl-x86-64:
   extends: .test-jobs-common