mtd: denali: update get nand para functions

In denali driver, wTotalBlocks variable is useless, so just
remove them in get_toshiba_nand_para and get_hynix_nand_para
first. Other wTotalBlocks in denali.c and other variables in
dev_info struct are also useless, will remove them later.

Also add a parameter in get_hynix_nand_para to prepare to
remove dev_info struct. This parameter comes by reading NAND
ID directly. Reading register will report wrong value for
some NAND chips, e.g. some Micron MT29F32G08QAA chips.
So update NAND_CMD_READID method as well.

Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>