ENGR00119324 Put GPMI NAND flash scan scheme code to the common NAND directory

1.GPMI NAND flash scan scheme can overcome the shortcomings
  of MTD NAND community code.

2.Put it to the common NAND directory can benifit I.MX NAND
  driver besides GPMI NAND driver.

3.Fix the section mismatch build warnings on ALL platforms.

4.Fix the kbuild build errors of I.MX platforms.

Signed-off-by: Jason Liu <r64343@freescale.com>

Signed-off-by: Bryan Wu <bryan.wu@canonical.com>