i2c: core: add managed function for adding i2c adapters

Some I2C controller drivers will only unregister the I2C
adapter in their .remove() callback, which can be done
by simply using a managed variant to add the I2C adapter.

So add the managed functions for adding the I2C adapter.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Yicong Yang <yangyicong@hisilicon.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>