gpio: Kconfig: Update help description for GPIO_RCAR config

The gpio-rcar 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>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/Kconfig

@@ -487,11 +487,11 @@ config GPIO_PXA
 	  Say yes here to support the PXA GPIO device
 
 config GPIO_RCAR
-	tristate "Renesas R-Car GPIO"
+	tristate "Renesas R-Car and RZ/G GPIO support"
 	depends on ARCH_RENESAS || COMPILE_TEST
 	select GPIOLIB_IRQCHIP
 	help
-	  Say yes here to support GPIO on Renesas R-Car SoCs.
+	  Say yes here to support GPIO on Renesas R-Car or RZ/G SoCs.
 
 config GPIO_RDA
 	bool "RDA Micro GPIO controller support"