An instance of a sensor on DT-based MMP2 platform is always going to be
created asynchronously.

Let's move the manual device creation away from the core to the Cafe
driver (used on OLPC XO-1, not present in DT) and set up appropriate
async matches: I2C on Cafe, FWNODE on MMP (OLPC XO-1.75).
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>