MFC r257892, r258196, r258197, r258199, r258200, r258201, r258202:

MFC r257892, r258196, r258197, r258199, r258200, r258201, r258202:

  Add ONFI signature check.

  Add Micron chip found in Freescale Vybrid Family Phytec COSMIC board.

  The vendor specified field is 88 bytes, not 8 bytes.

  Update the onfi_params struct to ONFI revision 3.2 (06 12 2013).

  Search for and validate the ONFI params as specified in the standard.

  ONFI parameters are little-endian, hence we must take care to convert them
  to native endianness.  We must also pay attention to unaligned accesses.

  Rework the routine that returns a pointer to the table of software ECC
  byte positions within the OOB area to support chips with unusual OOB
  sizes such as 218 or 224 bytes.