i2c: designware: allow IP specific sda_hold_time

Because some old designware IPs were not supporting setting an SDA hold
time, vendors developed their own solution. Add a way for the final driver
to provide its own SDA hold time handling.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>