rm_work: Ensure we don't remove sigbasedata files

We don't remove sigdata files, we also shouldn't remove sigbasedata files
as this hinders debugging.

(From OE-Core rev: 988349f90c8dc5498b1f08f71e99b13e928a0fd0)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/rm_work.bbclass

@@ -58,7 +58,7 @@ do_rm_work () {
             *do_setscene*)
                 break
                 ;;
-            *sigdata*)
+            *sigdata*|*sigbasedata*)
                 i=dummy
                 break
                 ;;