clocksource/drivers/sh_cmt: Mark "renesas,cmt-48-gen2" deprecated

Document in the driver that "renesas,cmt-48-gen2" is deprecated, but
still supported for backward compatibility with old DTBs, cfr. commit
4e18111f ("devicetree: bindings: Remove deprecated
properties").
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

drivers/clocksource/sh_cmt.c

@@ -935,7 +935,11 @@ MODULE_DEVICE_TABLE(platform, sh_cmt_id_table);
 
 static const struct of_device_id sh_cmt_of_table[] __maybe_unused = {
 	{ .compatible = "renesas,cmt-48", .data = &sh_cmt_info[SH_CMT_48BIT] },
-	{ .compatible = "renesas,cmt-48-gen2", .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2] },
+	{
+		/* deprecated, preserved for backward compatibility */
+		.compatible = "renesas,cmt-48-gen2",
+		.data = &sh_cmt_info[SH_CMT0_RCAR_GEN2]
+	},
 	{ .compatible = "renesas,rcar-gen2-cmt0", .data = &sh_cmt_info[SH_CMT0_RCAR_GEN2] },
 	{ .compatible = "renesas,rcar-gen2-cmt1", .data = &sh_cmt_info[SH_CMT1_RCAR_GEN2] },
 	{ }