dm: spi: Change cs_info op to return -EINVAL for invalid cs num

We need distinguish the following two situations in various SPI APIs:

- given chip select num is invalid
- given chip select num is valid, but no device is attached

Currently -ENODEV is returned for both cases.

For the first case, it's more reasonable to return -EINVAL instead of
-ENODEV for invalid chip select numbers.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Jagan Teki <jagan@amarulasolutions.com> # SoPine
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/drivers/spi/bcm63xx_spi.c b/drivers/spi/bcm63xx_spi.c
index 4d19e03..69f88c9 100644
--- a/drivers/spi/bcm63xx_spi.c
+++ b/drivers/spi/bcm63xx_spi.c
@@ -130,7 +130,7 @@
 
 	if (cs >= priv->num_cs) {
 		printf("no cs %u\n", cs);
-		return -ENODEV;
+		return -EINVAL;
 	}
 
 	return 0;