can: rcar_can: Fix erroneous registration

Assigning 2 to "renesas,can-clock-select" tricks the driver into
registering the CAN interface, even though we don't want that.
This patch improves one of the checks to prevent that from happening.

Fixes: 862e2b6a ("can: rcar_can: support all input clocks")
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Signed-off-by: Chris Paterson <Chris.Paterson2@renesas.com>
Reviewed-by: Simon Horman <horms+renesas@verge.net.au>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/rcar/rcar_can.c

@@ -24,6 +24,9 @@
 
 #define RCAR_CAN_DRV_NAME	"rcar_can"
 
+#define RCAR_SUPPORTED_CLOCKS	(BIT(CLKR_CLKP1) | BIT(CLKR_CLKP2) | \
+				 BIT(CLKR_CLKEXT))
+
 /* Mailbox configuration:
  * mailbox 60 - 63 - Rx FIFO mailboxes
  * mailbox 56 - 59 - Tx FIFO mailboxes
@@ -789,7 +792,7 @@ static int rcar_can_probe(struct platform_device *pdev)
 		goto fail_clk;
 	}
 
-	if (clock_select >= ARRAY_SIZE(clock_names)) {
+	if (!(BIT(clock_select) & RCAR_SUPPORTED_CLOCKS)) {
 		err = -EINVAL;
 		dev_err(&pdev->dev, "invalid CAN clock selected\n");
 		goto fail_clk;