mmc: renesas_sdhi: add R-Car Gen4 fallback compatibility string

For now, Gen4 is treated the same as Gen3. But we still want a seperate
fallback just in case.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Link: https://lore.kernel.org/r/20220603233300.21789-1-wsa+renesas@sang-engineering.comSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/renesas_sdhi_internal_dmac.c

@@ -268,6 +268,7 @@ static const struct of_device_id renesas_sdhi_internal_dmac_of_match[] = {
 	{ .compatible = "renesas,sdhi-r8a77990", .data = &of_r8a77990_compatible, },
 	{ .compatible = "renesas,sdhi-r8a77995", .data = &of_rcar_gen3_nohs400_compatible, },
 	{ .compatible = "renesas,rcar-gen3-sdhi", .data = &of_rcar_gen3_compatible, },
+	{ .compatible = "renesas,rcar-gen4-sdhi", .data = &of_rcar_gen3_compatible, },
 	{},
 };
 MODULE_DEVICE_TABLE(of, renesas_sdhi_internal_dmac_of_match);