mtd: gpmi: imx6: fix the wrong method for checking ready/busy

In the imx6, all the ready/busy pins are binding togeter.
So we should always check the ready/busy pin of the chip 0.

In the other word, when the CS1 is enabled, we should also check the
ready/busy of chip 0; if we check the ready/busy of chip 1,
we will get the wrong result.
Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

drivers/mtd/nand/gpmi-nand/gpmi-lib.c

@@ -1079,6 +1079,13 @@ int gpmi_is_ready(struct gpmi_nand_data *this, unsigned chip)
 		mask = MX23_BM_GPMI_DEBUG_READY0 << chip;
 		reg = readl(r->gpmi_regs + HW_GPMI_DEBUG);
 	} else if (GPMI_IS_MX28(this) || GPMI_IS_MX6Q(this)) {
+		/*
+		 * In the imx6, all the ready/busy pins are bound
+		 * together. So we only need to check chip 0.
+		 */
+		if (GPMI_IS_MX6Q(this))
+			chip = 0;
+
 		/* MX28 shares the same R/B register as MX6Q. */
 		mask = MX28_BF_GPMI_STAT_READY_BUSY(1 << chip);
 		reg = readl(r->gpmi_regs + HW_GPMI_STAT);