Restore coverage for conformance MATMUL

Increase size of tensor dimensions to meet compliance size needs.
Also improve warning output about this size requirement.

Signed-off-by: Jeremy Johnson <jeremy.johnson@arm.com>
Change-Id: I9dc2b8dab05a1bac0083cdca9d99845c287d3ce9
diff --git a/verif/conformance/tosa_main_profile_ops_info.json b/verif/conformance/tosa_main_profile_ops_info.json
index 0d3df72..054b9d4 100644
--- a/verif/conformance/tosa_main_profile_ops_info.json
+++ b/verif/conformance/tosa_main_profile_ops_info.json
@@ -1444,7 +1444,7 @@
                         "--fp-values-range",
                         "-2.0,2.0",
                         "--tensor-dim-range",
-                        "1,19"
+                        "10,19"
                     ],
                     [
                         "--target-dtype",