spi: sh-msiof: Drop comma after OF match table sentinel

It does not make sense to have a comma after a sentinel, as any new
elements must be added before the sentinel.

Add a comment to clarify the purpose of the empty element.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/2ab5745407339ba54b63c3e6410082c7c566bf95.1747401908.git.geert+renesas@glider.be
Signed-off-by: Mark Brown <broonie@kernel.org>

Author: geertu

drivers/spi/spi-sh-msiof.c

@@ -1101,7 +1101,7 @@ static const struct of_device_id sh_msiof_match[] __maybe_unused = {
 	{ .compatible = "renesas,rcar-gen3-msiof", .data = &rcar_gen3_data },
 	{ .compatible = "renesas,rcar-gen4-msiof", .data = &rcar_gen3_data },
 	{ .compatible = "renesas,sh-msiof",        .data = &sh_data }, /* Deprecated */
-	{},
+	{ /* sentinel */ }
 };
 MODULE_DEVICE_TABLE(of, sh_msiof_match);