nand, atmel: remove udelay in spl_nand_erase_one()

remove unneeded udelay() in this function, as we use
the dev_ready pin.

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Scott Wood <scottwood@freescale.com>
diff --git a/drivers/mtd/nand/atmel_nand.c b/drivers/mtd/nand/atmel_nand.c
index a2016e7..0d4f327 100644
--- a/drivers/mtd/nand/atmel_nand.c
+++ b/drivers/mtd/nand/atmel_nand.c
@@ -1378,9 +1378,7 @@
 	hwctrl(&mtd, (page_addr >> 16) & 0x0f,
 	       NAND_CTRL_ALE | NAND_CTRL_CHANGE);
 #endif
-
 	hwctrl(&mtd, NAND_CMD_ERASE2, NAND_CTRL_CLE | NAND_CTRL_CHANGE);
-	udelay(2000);
 
 	while (!this->dev_ready(&mtd))
 		;