patch: make i2c(8) usable for scripting

[Ian Lepore]

On Sat, 2021-05-15 at 20:14 +0000, Poul-Henning Kamp wrote:
> The /dev/iic%d filedescriptor is opened and closed for every single
> command, in the hope that it will aid multiple separate programs
> sharing I2C busses.  I have not actually tried that yet, so it may
> need more work (exclusive opens etc.).

There should be no need to do that.  The i2c bus is arbitrated in
iicbus/iiconf.c and most all the in-tree drivers now use either
explicit iicbus_request_bus() calls, or use iicbus_transfer_excl(). 
Certainly users of iic(4) don't need to be protected from each other;
everything in the driver that uses the bus does so inside of
request_bus / release_bus calls.

-- Ian