As discussed previously the best location for certain bus related bits,
e.g. I2C, is its own realm of the headers.

In order to uncontaminate acpi.h move the I2C bits to i2c.h.

There is no functional change intended.

Link: https://lkml.org/lkml/2018/11/28/744Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: NMika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>