* MTD generic binding

- nand-ecc-mode : String, operation mode of the NAND ecc mode.
  Supported values are: "none", "soft", "hw", "hw_syndrome", "hw_oob_first",
  "soft_bch".
- nand-bus-width : 8 or 16 bus width if not present 8
- nand-on-flash-bbt: boolean to enable on flash bbt option if not present false

- nand-ecc-strength: integer representing the number of bits to correct
		     per ECC step.

- nand-ecc-step-size: integer representing the number of data bytes
		      that are covered by a single ECC step.

The ECC strength and ECC step size properties define the correction capability
of a controller. Together, they say a controller can correct "{strength} bit
errors per {size} bytes".

The interpretation of these parameters is implementation-defined, so not all
implementations must support all possible combinations. However, implementations
are encouraged to further specify the value(s) they support.
