reformat the coding style in rthw.h

include/rthw.h

@@ -56,7 +56,8 @@ rt_uint8_t *rt_hw_stack_init(void       *entry,
  */
 typedef void (*rt_isr_handler_t)(int vector, void *param);
 
-struct rt_irq_desc {
+struct rt_irq_desc
+{
     rt_isr_handler_t handler;
     void            *param;
 
@@ -95,7 +96,7 @@ void rt_hw_show_memory(rt_uint32_t addr, rt_uint32_t size);
 /*
  * Exception interfaces
  */
-void rt_hw_exception_install(rt_err_t (*exception_handle)(void* context));
+void rt_hw_exception_install(rt_err_t (*exception_handle)(void *context));
 
 #ifdef __cplusplus
 }