Allocate an explicit i2c mux core to handle parent and child adapters
etc. Update the select/deselect ops to be in terms of the i2c mux core
instead of the child adapter.
Tested-by: NAntti Palosaari <crope@iki.fi>
Reviewed-by: NAntti Palosaari <crope@iki.fi>
Signed-off-by: NPeter Rosin <peda@axentia.se>
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>