EXT_WAKEUP test minor improvements.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@3344 35acf78f-673a-0410-8e92-d51de3d6d3f4

testhal/STM32F1xx/EXT_WAKEUP/main.c

@@ -32,7 +32,7 @@ static void extcb2(EXTDriver *extp, expchannel_t channel) {
   (void)channel;
 
   chSysLockFromIsr();
-  /* we MUST reinit clocks after waking up*/
+  /* we MUST reinit clocks after waking up if use HSE or HSI+PLL */
   stm32_clock_init();
 
   extChannelDisableI(&EXTD1, 10);