rtc: st: Update IP layout information to include Clocksource

Initial submission adding support for this IP only included Watchdog and
the Real-Time Clock.  Now the third (and final) device is enabled this
trivial patch is required to update the comment in the RTC driver to
encompass Clocksource.
Acked-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/rtc/rtc-st-lpc.c

@@ -208,7 +208,7 @@ static int st_rtc_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	/* LPC can either run in RTC or WDT mode */
+	/* LPC can either run as a Clocksource or in RTC or WDT mode */
 	if (mode != ST_LPC_MODE_RTC)
 		return -ENODEV;