can: rcar: Kconfig: update help description for CAN_RCAR config

The rcar_can driver also supports RZ/G SoC's, update the description to reflect
this.
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20210104090327.6547-1-prabhakar.mahadev-lad.rj@bp.renesas.comSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>

drivers/net/can/rcar/Kconfig

 # SPDX-License-Identifier: GPL-2.0
 config CAN_RCAR
-	tristate "Renesas R-Car CAN controller"
+	tristate "Renesas R-Car and RZ/G CAN controller"
 	depends on ARCH_RENESAS || ARM
 	help
 	  Say Y here if you want to use CAN controller found on Renesas R-Car
-	  SoCs.
+	  or RZ/G SoCs.
 
 	  To compile this driver as a module, choose M here: the module will
 	  be called rcar_can.