i2c: designware: Make register offsets all of the same width

For the sake of consistency add leading 0 to first register offsets
to make them all of the same width.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>