ci: only build ux900fd_sd image for github.

Signed-off-by: matthew.gui <guibing@nuclei.com>

Author: matthew.gui

.github/workflows/build.yml

@@ -29,7 +29,7 @@ jobs:
     strategy:
       matrix:
         soc: [evalsoc]
-        core: [ux900, ux900fd]
+        core: [ux900fd]
         boot_mode: [sd]
 
     # Steps represent a sequence of tasks that will be executed as part of the job