[Kernel] Add build time to the boot printing

When the firmware is built many times in a day, we can not distinguish
them by current boot printing for the lack of compile time. So, it is
necessary to add __TIME__ to rt_show_version().
Signed-off-by: nrush <1741598985@qq.com>

src/kservice.c

@@ -546,8 +546,8 @@ void rt_show_version(void)
 {
     rt_kprintf("\n \\ | /\n");
     rt_kprintf("- RT -     Thread Operating System\n");
-    rt_kprintf(" / | \\     %d.%d.%d build %s\n",
-               RT_VERSION, RT_SUBVERSION, RT_REVISION, __DATE__);
+    rt_kprintf(" / | \\     %d.%d.%d build %s %s\n",
+               RT_VERSION, RT_SUBVERSION, RT_REVISION, __DATE__, __TIME__);
     rt_kprintf(" 2006 - 2021 Copyright by rt-thread team\n");
 }
 RTM_EXPORT(rt_show_version);