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/mscc_bb_spi.c b/drivers/spi/mscc_bb_spi.c
index ad4daeb..75ab4ab 100644
--- a/drivers/spi/mscc_bb_spi.c
+++ b/drivers/spi/mscc_bb_spi.c
@@ -123,11 +123,11 @@
 	u8		*rxd = din;
 
 	debug("spi_xfer: slave %s:%s cs%d mode %d, dout %p din %p bitlen %u\n",
-	      dev->parent->name, dev->name, plat->cs,  plat->mode, dout,
+	      dev->parent->name, dev->name, plat->cs[0],  plat->mode, dout,
 	      din, bitlen);
 
 	if (flags & SPI_XFER_BEGIN)
-		mscc_bb_spi_cs_activate(priv, plat->mode, plat->cs);
+		mscc_bb_spi_cs_activate(priv, plat->mode, plat->cs[0]);
 
 	count = bitlen / 8;
 	for (i = 0; i < count; i++) {