[PATCH] I2C: add i2c driver for TPS6501x

This adds an I2C driver for the TPS6501x series of power management chips.
It's used on many OMAP based boards, and this driver has been widely used
in the Linux-OMAP trees over the last year or so.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>