mtd: rawnand: fsmc: Take instruction delay into account

The FSMC NAND controller should apply a delay after the
instruction has been issued on the bus.
The FSMC NAND controller driver did not handle this delay.

Add this waiting delay in the FSMC NAND controller driver.

Fixes: 4da712e ("mtd: nand: fsmc: use ->exec_op()")
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20211119150316.43080-4-herve.codina@bootlin.com

drivers/mtd/nand/raw/fsmc_nand.c

@@ -15,6 +15,7 @@
 
 #include <linux/clk.h>
 #include <linux/completion.h>
+#include <linux/delay.h>
 #include <linux/dmaengine.h>
 #include <linux/dma-direction.h>
 #include <linux/dma-mapping.h>
@@ -664,6 +665,9 @@ static int fsmc_exec_op(struct nand_chip *chip, const struct nand_operation *op,
 						instr->ctx.waitrdy.timeout_ms);
 			break;
 		}
+
+		if (instr->delay_ns)
+			ndelay(instr->delay_ns);
 	}
 
 	return ret;