Add support for Maxim/Dallas DS1374 Real-Time Clock Chip

This change adds support for the Maxim/Dallas DS1374 RTC chip. This chip
is an I2C-based RTC that maintains a simple 32-bit binary seconds count
with battery backup support.
Signed-off-by: NRandy Vinson <rvinson@mvista.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>