[PATCH] I2C: m41t00: Add support for the ST M41T81 and M41T85

[PATCH] I2C: m41t00: Add support for the ST M41T81 and M41T85

This patch adds support for the ST m41t81 and m41t85 i2c rtc chips
to the existing m41t00 driver.

Since there is no way to reliably determine what type of rtc chip
is in use, the chip type is passed in via platform_data.  The i2c
address and square wave frequency are passed in via platform_data
as well.  To accommodate the use of platform_data, a new header
file include/linux/m41t00.h has been added.

The m41t81 and m41t85 chips halt the updating of their time registers
while they are being accessed.  They resume when a stop condition
exists on the i2c bus or when non-time related regs are accessed.
To make the best use of that facility and to make more efficient
use of the i2c bus, this patch replaces multiple i2c_smbus_xxx calls
with a single i2c_transfer call.

Signed-off-by: Mark A. Greer <mgreer@mvista.com>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>