rtc: add support for spi rtc rx4581

[akpm@linux-foundation.org: checkpatch fixes]
Signed-off-by: Torben Hohn <torbenh@linutronix.de>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/rtc/Kconfig

@@ -561,6 +561,14 @@ config RTC_DRV_PCF2123
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-pcf2123.
 
+config RTC_DRV_RX4581
+	tristate "Epson RX-4581"
+	help
+	  If you say yes here you will get support for the Epson RX-4581.
+
+	  This driver can also be built as a module. If so the module
+	  will be called rtc-rx4581.
+
 endif # SPI_MASTER
 
 comment "Platform RTC drivers"