rtc: add support for the S-35390A RTC chip

This adds basic get/set time support for the Seiko Instruments S-35390A.
This chip communicates using I2C and is used on the QNAP TS-109/TS-209 NAS
devices.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Byron Bradley <byron.bbradley@gmail.com>
Acked-by: Jean Delvare <khali@linux-fr.org>
Acked-by: David Brownell <david-b@pacbell.net>
Tested-by: Tim Ellis <tim@ngndg.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 6402d69..82f5ad9 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -250,6 +250,15 @@
 	  platforms.  The support is integrated with the rest of
 	  the Menelaus driver; it's not separate module.
 
+config RTC_DRV_S35390A
+	tristate "Seiko Instruments S-35390A"
+	help
+	  If you say yes here you will get support for the Seiko
+	  Instruments S-35390A.
+
+	  This driver can also be built as a module. If so the module
+	  will be called rtc-s35390a.
+
 endif # I2C
 
 comment "SPI RTC drivers"