Add I2C bus related APIs to initialize I2C sub-system parameters, such
as bus speed, slave address, address bit. As I2C sub-system hasn't
auto register save and restore support, provide APIs to do it manually.
Co-developed-by: Xinpeng Sun <xinpeng.sun@intel.com> Signed-off-by: Xinpeng Sun <xinpeng.sun@intel.com> Signed-off-by: Even Xu <even.xu@intel.com> Tested-by: Rui Zhang <rui1.zhang@intel.com> Tested-by: Mark Pearson <mpearson-lenovo@squebb.ca> Reviewed-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca> Tested-by: Aaron Ma <aaron.ma@canonical.com> Signed-off-by: Jiri Kosina <jkosina@suse.com>