pxa3xx_nand: adjust timing of Micron NAND flash

Slow down the tRp of Micron NAND flash timing.

Signed-off-by: Haojian Zhuang <haojian.zhuang@marvell.com>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
index 9140fdc..a085cd0 100644
--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -235,7 +235,7 @@
 	.tWH	= 15,
 	.tWP	= 25,
 	.tRH	= 15,
-	.tRP	= 25,
+	.tRP	= 30,
 	.tR	= 25000,
 	.tWHR	= 60,
 	.tAR	= 10,