v4l2-decoder-conformance: Use correct base test job

Fluster tests were previously triggered by successful kernel build in
kbuild-gcc-12-arm64-chromebook configuration. It had to be replaced by
a job depending on kbuild-gcc-12-arm64-chromeos-mediatek kernel build
events - otherwise wrong defconfig was in use.

Signed-off-by: Paweł Wieczorek <[email protected]>

config/scheduler-chromeos.yaml

@@ -523,35 +523,35 @@ scheduler:
       - mt8195-cherry-tomato-r2
 
   - job: fluster-chromeos-av1
-    <<: *test-job-arm64-mediatek
+    <<: *test-job-chromeos-mediatek
     platforms:
       - mt8195-cherry-tomato-r2
 
   - job: fluster-chromeos-av1-chromium-10bit
-    <<: *test-job-arm64-mediatek
+    <<: *test-job-chromeos-mediatek
     platforms:
       - mt8195-cherry-tomato-r2
 
   - job: fluster-chromeos-h264
-    <<: *test-job-arm64-mediatek
+    <<: *test-job-chromeos-mediatek
 
   - job: fluster-chromeos-h264-frext
-    <<: *test-job-arm64-mediatek
+    <<: *test-job-chromeos-mediatek
 
   - job: fluster-chromeos-h265
-    <<: *test-job-arm64-mediatek
+    <<: *test-job-chromeos-mediatek
     platforms:
       - mt8195-cherry-tomato-r2
 
   - job: fluster-chromeos-vp8
-    <<: *test-job-arm64-mediatek
+    <<: *test-job-chromeos-mediatek
     platforms:
       - mt8186-corsola-steelix-sku131072
       - mt8192-asurada-spherion-r0
       - mt8195-cherry-tomato-r2
 
   - job: fluster-chromeos-vp9
-    <<: *test-job-arm64-mediatek
+    <<: *test-job-chromeos-mediatek
     platforms:
       - mt8186-corsola-steelix-sku131072
       - mt8192-asurada-spherion-r0