rtc: Add M41T62 support

This patch add support for the STM M41T62 RTC. It is used and tested
on the AMCC Canyonlands 406EX platform.

Signed-off-by: Stefan Roese <sr@denx.de>

drivers/rtc/Makefile

@@ -41,6 +41,7 @@ COBJS-y += ds174x.o
 COBJS-y += ds3231.o
 COBJS-y += m41t11.o
 COBJS-y += m41t60.o
+COBJS-$(CONFIG_RTC_M41T62) += m41t62.o
 COBJS-y += max6900.o
 COBJS-y += m48t35ax.o
 COBJS-y += mc146818.o