[sw/mask_rom] Force manifest.h dependency.

Ensure manifest.h is defined as a dependency of the mask_rom library.

Signed-off-by: Miguel Osorio <miguelosorio@google.com>
diff --git a/sw/device/silicon_creator/mask_rom/meson.build b/sw/device/silicon_creator/mask_rom/meson.build
index e193d2b..64da64a 100644
--- a/sw/device/silicon_creator/mask_rom/meson.build
+++ b/sw/device/silicon_creator/mask_rom/meson.build
@@ -33,7 +33,10 @@
     ],
     link_with: static_library(
       'mask_rom_lib',
-      sources: ['mask_rom.c'],
+      sources: [
+        rom_exts_manifest_offsets_header,
+        'mask_rom.c'
+      ],
       link_depends: [rom_linkfile],
   )
 )