i2c: Add a new API test using (f/s/nv)ram

RAM allows for very fast reads and writes and lets us explore most of
the I2C controller APIs including RTIO. Theoretically supports any form
of i2c connected RAM but requires some tweaking to work with specific
parts potentially. Tested with Fujitsu's MB85 FeRAM part using an
arduino breakout.

Signed-off-by: Tom Burdick <thomas.burdick@intel.com>