Test support for alternative conv layout (llama/25617)

* add  bool cwhn = true to conv_2d test cases

* add layout check at graph building time

* extend layout checks for conv2d.cu kernel

* in CPU back-end kernel needs to be stored contiguously to prevent test failures with cwhn=1

* trim white space

* do op support check in vulkan backend

* fix CI failure and vulkan run-time assert failure by introducing new graph build-time check in ggml_backend_vk_device_supports_op

* add additional check in support_op function for Vulkan to fix run-time assert failure

ggml/src/ggml-cpu/ggml-cpu.cpp

@@ -469,6 +469,8 @@ static bool ggml_backend_cpu_device_supports_op(ggml_backend_dev_t dev, const st
             return (src0->type == GGML_TYPE_F32 ||
                     ((src0->type == GGML_TYPE_F16 || ggml_is_quantized(src0->type)) && src0->ne[2] == src1->ne[2] && src0->ne[3] == src1->ne[3])) &&
                 src1->type == GGML_TYPE_F32 && op->type == GGML_TYPE_F32;
+        case GGML_OP_CONV_2D:
+            return ggml_is_contiguous(op->src[0]);
         default:
             return true;
     }