Renaming iree_hal_executable_spec_t -> .._params_t. (#8470)

Matches the style of other parameter structs.
diff --git a/experimental/rocm/native_executable.h b/experimental/rocm/native_executable.h
index 4ebf017..59882b7 100644
--- a/experimental/rocm/native_executable.h
+++ b/experimental/rocm/native_executable.h
@@ -22,7 +22,7 @@
 // kernels that can be extracted along with the associated block size.
 iree_status_t iree_hal_rocm_native_executable_create(
     iree_hal_rocm_context_wrapper_t* context,
-    const iree_hal_executable_spec_t* executable_spec,
+    const iree_hal_executable_params_t* executable_params,
     iree_hal_executable_t** out_executable);
 
 hipFunction_t iree_hal_rocm_native_executable_for_entry_point(