kernel:add a some information in backtraces.

* Display the pid and process name in the backtrace as we can
currently not read stackframes.

Change-Id: I2435d4098553c5b02adfe36f08b5aa3f47e9b531

kernel/arch/arm/exception.c

@@ -204,6 +204,8 @@ void exception_handler(int is_nested, reg_t *saved_lr, int vector)
  *===========================================================================*/
 static void proc_stacktrace_execute(struct proc *whichproc, reg_t v_bp, reg_t pc)
 {
+	printf("%-8.8s %6d 0x%lx \n",
+		whichproc->p_name, whichproc->p_endpoint, pc);
 }
 #endif