drivers: mtd: nand: cadence: Add support for read status command

Add support for read status command
in Cadence NAND driver. This status bit is important to check
whether the flash is write-protected.

Signed-off-by: Dinesh Maniyam <dinesh.maniyam@intel.com>

include/cadence-nand.h

@@ -454,6 +454,8 @@ struct cadence_nand_info {
 	u8 *buf;
 	u32 buf_size;
 	u8 *stat;
+	u8 cmd;
+	u32 buf_index;
 
 	u8 curr_corr_str_idx;