Staging: iio: trigger: Add module name information in Kconfig

This patch updates Kconfig with paragraphs that describe config symbol fully.
Found using checkpatch.pl.
Signed-off-by: Darshana Padmadas <darshanapadmadas@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/iio/trigger/Kconfig

-#
+  #
 # Industrial I/O standalone triggers
 #
 comment "Triggers - standalone"
@@ -12,6 +12,9 @@ config IIO_PERIODIC_RTC_TRIGGER
 	  Provides support for using periodic capable real time
 	  clocks as IIO triggers.
 
+	  To compile this driver as a module, choose M here: the
+	  module will be called iio-trig-periodic-rtc.
+
 config IIO_BFIN_TMR_TRIGGER
 	tristate "Blackfin TIMER trigger"
 	depends on BLACKFIN