Fix trivial typos in Kconfig* files

Fix several typos in help text in Kconfig* files.

Signed-off-by: David Sterba <dave@jikos.cz>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 5e43983..76422ed 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -98,7 +98,7 @@
 	bool "RTC UIE emulation on dev interface"
 	depends on RTC_INTF_DEV
 	help
-	  Provides an emulation for RTC_UIE if the underlaying rtc chip
+	  Provides an emulation for RTC_UIE if the underlying rtc chip
 	  driver does not expose RTC_UIE ioctls.  Those requests generate
 	  once-per-second update interrupts, used for synchronization.