can: rcar_can: Remove unused platform data support

All R-Car platforms use DT for describing CAN controllers. R-Car CAN
platform data support was never used in any upstream kernel.

Move the Clock Select Register settings enum into the driver, and remove
platform data support and the corresponding header file.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

include/linux/can/platform/rcar_can.h

@@ -1,18 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _CAN_PLATFORM_RCAR_CAN_H_
-#define _CAN_PLATFORM_RCAR_CAN_H_
-
-#include <linux/types.h>
-
-/* Clock Select Register settings */
-enum CLKR {
-	CLKR_CLKP1 = 0,	/* Peripheral clock (clkp1) */
-	CLKR_CLKP2 = 1,	/* Peripheral clock (clkp2) */
-	CLKR_CLKEXT = 3	/* Externally input clock */
-};
-
-struct rcar_can_platform_data {
-	enum CLKR clock_select;	/* Clock source select */
-};
-
-#endif	/* !_CAN_PLATFORM_RCAR_CAN_H_ */