amdgpu: add max_memory_clock for interface query

Signed-off-by: Ken Wang <Qingqing.Wang@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
diff --git a/amdgpu/amdgpu.h b/amdgpu/amdgpu.h
index c6161bd..17e5c1a 100644
--- a/amdgpu/amdgpu.h
+++ b/amdgpu/amdgpu.h
@@ -478,6 +478,8 @@
 	uint64_t ids_flags;
 	/** max engine clock*/
 	uint64_t max_engine_clk;
+	/** max memory clock */
+	uint64_t max_memory_clk;
 	/** number of shader engines */
 	uint32_t num_shader_engines;
 	/** number of shader arrays per engine */