NAND: add NAND_CMD_PARAM (0xec) definition

This command is used to read the device ONFI parameters page.

Signed-off-by: Florian Fainelli <florian@openwrt.org>

include/linux/mtd/nand.h

@@ -84,6 +84,7 @@ extern void nand_wait_ready(struct mtd_info *mtd);
 #define NAND_CMD_SEQIN		0x80
 #define NAND_CMD_RNDIN		0x85
 #define NAND_CMD_READID		0x90
+#define NAND_CMD_PARAM		0xec
 #define NAND_CMD_ERASE2		0xd0
 #define NAND_CMD_RESET		0xff