I2C: OMAP: add rev to omap i2c platform data

We need to pass the I2C IP revision from the hwmod class up
into the OMAP I2C driver, which does not have direct
access to it.

This adds a member to the platform data the OMAP I2C driver
does use already to hold the I2C IP revision.

Cc: patches@linaro.org
Cc: Ben Dooks <ben-linux@fluff.org>
Reported-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Andy Green <andy.green@linaro.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>