i2c: ismt: Add Seth and Myself as maintainers

Adding Seth Heasley and Myself as maintainers for the i2c-ismt drvier

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: "Heasley, Seth" <seth.heasley@intel.com>
Reviewed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Wolfram Sang <wolfram@the-dreams.de>