mtd: mxc-nand: kill the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE
We kill the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE by the following way:
1.) Before we call the nand_scan_ident, we allocate a temporary buffer
whose size is PAGE_SIZE.
2.) After we finish the nand_scan_ident, we have already getten the
page size and oob size. We will allocate the right buffer size
again.