Convert the smfc object to be specific to a single smfc channel.
Add ipu_smfc_{get|put} to retrieve and release a single smfc channel
for exclusive use, and add use counter to ipu_smfc_{enable|disable}.
Signed-off-by: NSteve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Move the SMFC module enable/disable helpers into the ipu-smfc submodule.
Signed-off-by: NSteve Longerbeam <steve_longerbeam@mentor.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

The Sensor Multi Fifo Controller (SMFC) is used as a buffer between
the two CSIs (writing simultaneously) and up to four IDMAC channels.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>