Fix typo in various Kconfig file

Correct spelling typo in various Kconfig file.

Signed-off-by: Masanari Iida <standby24x7@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig
index cd9bc3b..b4b918a 100644
--- a/drivers/ptp/Kconfig
+++ b/drivers/ptp/Kconfig
@@ -70,7 +70,7 @@
 	  using the SO_TIMESTAMPING API.
 
 	  In order for this to work, your MAC driver must also
-	  implement the skb_tx_timetamp() function.
+	  implement the skb_tx_timestamp() function.
 
 config PTP_1588_CLOCK_PCH
 	tristate "Intel PCH EG20T as PTP clock"