mtd: nand: mxs: fix PIO_WORDs in mxs_nand_write_buf()

There is only one pio_word in this DMA transaction so data field must be 1.
Signed-off-by: NLuca Ellero <luca.ellero@brickedbrain.com>

drivers/mtd/nand/mxs_nand.c

@@ -510,7 +510,7 @@ static void mxs_nand_write_buf(struct mtd_info *mtd, const uint8_t *buf,
 	d->cmd.data =
 		MXS_DMA_DESC_COMMAND_DMA_READ | MXS_DMA_DESC_IRQ |
 		MXS_DMA_DESC_DEC_SEM | MXS_DMA_DESC_WAIT4END |
-		(4 << MXS_DMA_DESC_PIO_WORDS_OFFSET) |
+		(1 << MXS_DMA_DESC_PIO_WORDS_OFFSET) |
 		(length << MXS_DMA_DESC_BYTES_OFFSET);
 
 	d->cmd.address = (dma_addr_t)nand_info->data_buf;