spi: spi-uclass: Read chipselect and restrict capabilities

Read chipselect properties from DT which are populated using 'reg'
property and save it in plat->cs[] array for later use.

Also read multi chipselect capability which is used for
parallel-memories and return errors if they are passed on using DT but
driver is not capable of handling it.

Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Signed-off-by: Venkatesh Yadav Abbarapu <venkatesh.abbarapu@amd.com>
diff --git a/drivers/spi/fsl_espi.c b/drivers/spi/fsl_espi.c
index 2638ed2..7ed35aa 100644
--- a/drivers/spi/fsl_espi.c
+++ b/drivers/spi/fsl_espi.c
@@ -513,8 +513,8 @@
 	struct udevice *bus = dev->parent;
 	struct fsl_spi_slave *fsl = dev_get_priv(bus);
 
-	debug("%s cs %u\n", __func__, slave_plat->cs);
-	fsl->cs = slave_plat->cs;
+	debug("%s cs %u\n", __func__, slave_plat->cs[0]);
+	fsl->cs = slave_plat->cs[0];
 
 	return 0;
 }