rtc: rtc-m41t80.c: add support for the ST M41T65 RTC

Add support for M41T65 Real Time Clock chip.

The main differences I see between the M41T65 and M41T80 are that:

1) The M41T65 watchdog timer has three bits controlling resolution
   (versus two for the M41T80).

2) There is no register 0x13 for controlling square-wave output.

Signed-off-by: Steven A. Falco <sfalco@harris.com>
Acked-by: Alessandro Zummo <a.zummo@towertech.it>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Acked-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Cc: David Brownell <david-b@pacbell.net>
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 1a94596..f660ef3 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -220,22 +220,22 @@
 	  will be called rtc-pcf8583.
 
 config RTC_DRV_M41T80
-	tristate "ST M41T80/81/82/83/84/85/87"
+	tristate "ST M41T65/M41T80/81/82/83/84/85/87"
 	help
-	  If you say Y here you will get support for the
-	  ST M41T80 RTC chips series. Currently following chips are
-	  supported: M41T80, M41T81, M41T82, M41T83, M41ST84, M41ST85
-	  and M41ST87.
+	  If you say Y here you will get support for the ST M41T60
+	  and M41T80 RTC chips series. Currently, the following chips are
+	  supported: M41T65, M41T80, M41T81, M41T82, M41T83, M41ST84,
+	  M41ST85, and M41ST87.
 
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-m41t80.
 
 config RTC_DRV_M41T80_WDT
-	bool "ST M41T80 series RTC watchdog timer"
+	bool "ST M41T65/M41T80 series RTC watchdog timer"
 	depends on RTC_DRV_M41T80
 	help
 	  If you say Y here you will get support for the
-	  watchdog timer in ST M41T80 RTC chips series.
+	  watchdog timer in the ST M41T60 and M41T80 RTC chips series.
 
 config RTC_DRV_TWL92330
 	boolean "TI TWL92330/Menelaus"