spi: fsl_qspi: Add support for single chip select

SOC’s like LS1012A has only one chip select signal for QSPI flash.
Avoid scanning other flash.

Signed-off-by: Suresh Gupta <suresh.gupta@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/drivers/spi/fsl_qspi.c b/drivers/spi/fsl_qspi.c
index b2a0583..e61c67b 100644
--- a/drivers/spi/fsl_qspi.c
+++ b/drivers/spi/fsl_qspi.c
@@ -1037,8 +1037,11 @@
 	 * setting the size of these devices to 0.  This would ensure
 	 * that the complete memory map is assigned to only one flash device.
 	 */
-	qspi_write32(priv->flags, &priv->regs->sfa1ad, priv->amba_base[1]);
+	qspi_write32(priv->flags, &priv->regs->sfa1ad,
+		     priv->amba_base[0] + amba_size_per_chip);
 	switch (priv->num_chipselect) {
+	case 1:
+		break;
 	case 2:
 		qspi_write32(priv->flags, &priv->regs->sfa2ad,
 			     priv->amba_base[1]);