mtd: nand: Allow caller to pass alternative ID table to nand_scan_ident()

This patch sync with David's patch on Linux for handling nand_scan_ident.

	commit 5e81e88a4c140586d9212999cea683bcd66a15c6
	Author: David Woodhouse <David.Woodhouse@intel.com>
	Date:   Fri Feb 26 18:32:56 2010 +0000

	mtd: nand: Allow caller to pass alternative ID table to nand_scan_ident()

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

Signed-off-by: Lei Wen <leiwen@marvell.com>