- Changes in Kconfig to enable I2C_DESIGNWARE_SLAVE support
- Slave functions added to core library file
- Slave abort sources added to common source file
- New driver: i2c-designware-slave added
- Changes in the Makefile to compile the I2C_DESIGNWARE_SLAVE module
  when supported by the architecture.

All the SLAVE flow is added but it is not enabled via platform
driver.
Signed-off-by: NLuis Oliveira <lolivei@synopsys.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NJarkko Nikula <jarkko.nikula@linux.intel.com>
[wsa: made a function static and one-lined a message]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>