thermal/drivers/rcar_gen3: Document Gen4 support in Kconfig entry

The R-Car Gen3 thermal driver supports both R-Car Gen3 and Gen4 SoCs.
Update the Kconfig entry.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Link: https://lore.kernel.org/r/20250905193322.148115-1-marek.vasut+renesas@mailbox.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

Author: Marek Vasut

drivers/thermal/renesas/Kconfig

@@ -10,13 +10,13 @@ config RCAR_THERMAL
 	  thermal framework.
 
 config RCAR_GEN3_THERMAL
-	tristate "Renesas R-Car Gen3 and RZ/G2 thermal driver"
+	tristate "Renesas R-Car Gen3/Gen4 and RZ/G2 thermal driver"
 	depends on ARCH_RENESAS || COMPILE_TEST
 	depends on HAS_IOMEM
 	depends on OF
 	help
-	  Enable this to plug the R-Car Gen3 or RZ/G2 thermal sensor driver into
-	  the Linux thermal framework.
+	  Enable this to plug the R-Car Gen3/Gen4 or RZ/G2 thermal sensor
+	  driver into the Linux thermal framework.
 
 config RZG2L_THERMAL
 	tristate "Renesas RZ/G2L thermal driver"