misc: eeprom_93xx46: Implement eeprom_93xx46 DT bindings.

This commit implements bindings in the eeprom_93xx46 driver allowing
device word size and read-only attributes to be specified via
devicetree.

Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com>
Tested-by: Chris Healy <chris.healy@zii.aero>
Reviewed-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>