disable unsupported head sizes for AMD in test

Author: JohannesGaessler

tests/test-backend-ops.cpp

@@ -2173,7 +2173,11 @@ static bool test_backend(ggml_backend_t backend, test_mode mode, const char * op
     test_cases.emplace_back(new test_timestep_embedding());
     test_cases.emplace_back(new test_leaky_relu());
 
+#if defined(GGML_USE_HIPBLAS) && defined(__HIP_PLATFORM_AMD__)
+    for (int hs : { 64, 128, }) { // other head sizes not implemented
+#else
     for (int hs : { 64, 80, 128, 256, }) {
+#endif // defined(GGML_USE_HIPBLAS) && defined(__HIP_PLATFORM_AMD__)
         for (int nh : { 32, }) {
             for (int kv : { 512, 1024, }) {
                 for (int nb : { 1, 2, 4, 8, }) {