spi: atmel-quadspi: Fix the buswidth adjustment between spi-mem and controller

Use the spi_mem_default_supports_op() core helper in order to take into
account the buswidth specified by the user in device tree.

Fixes: 24c8ff4684 ("spi: Add Atmel QuadSPI driver")
Signed-off-by: Tudor Ambarus <tudor.ambarus@microchip.com>
diff --git a/drivers/spi/atmel-quadspi.c b/drivers/spi/atmel-quadspi.c
index 0982983..cb64119 100644
--- a/drivers/spi/atmel-quadspi.c
+++ b/drivers/spi/atmel-quadspi.c
@@ -438,6 +438,9 @@
 {
 	struct atmel_qspi *aq = dev_get_priv(slave->dev->parent);
 
+	if (!spi_mem_default_supports_op(slave, op))
+		return false;
+
 	if (aq->caps->octal) {
 		if (atmel_qspi_sama7g5_find_mode(op) < 0)
 			return false;