spi: atmel-quadspi: Fix wrong register value written to MR

aq->mr should go to MR, nothing else.

Fixes: 329ca3eed4a9 ("spi: atmel-quadspi: Avoid overwriting delay register settings")
Signed-off-by: Alexander Dahl <[e-mail]>
Link: https://lore.kernel.org/linux-spi/[e-mail]/T/#u
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/spi/atmel-quadspi.c

···
 	 */
 	if (!(aq->mr & QSPI_MR_SMM)) {
 		aq->mr |= QSPI_MR_SMM;
-		atmel_qspi_write(aq->scr, aq, QSPI_MR);
+		atmel_qspi_write(aq->mr, aq, QSPI_MR);
 	}
 
 	/* Clear pending interrupts */