clk: ralink: mtmips: quiet unused variable warning

When CONFIG_OF is disabled then the matching table is not referenced and
the following warning appears:

drivers/clk/ralink/clk-mtmips.c:821:34: warning: unused variable 'mtmips_of_match' [-Wunused-const-variable]
821 |   static const struct of_device_id mtmips_of_match[] = {
    |                          ^

There are two match tables in the driver: one for the clock driver and the
other for the reset driver. The only difference between them is that the
clock driver uses 'data' and does not have 'ralink,rt2880-reset' compatible.
Both just can be merged into a single one just by adding the compatible
'ralink,rt2880-reset' entry to 'mtmips_of_match[]', which will allow it to
be used for 'mtmips_clk_driver' (which doesn't use the data) as well as for
'mtmips_clk_init()' (which doesn't need get called for 'ralink,rt2880-reset').

Doing in this way ensures that 'CONFIG_OF' is not disabled anymore so the
above warning disapears.

Fixes: 6f3b1558 ("clk: ralink: add clock and reset driver for MTMIPS SoCs")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202307242310.CdOnd2py-lkp@intel.com/Suggested-by: Arnd Bergmann <arnd@kernel.org>
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20230827023932.501102-1-sergio.paracuellos@gmail.comReviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/ralink/clk-mtmips.c

@@ -821,6 +821,10 @@ static const struct mtmips_clk_data mt76x8_clk_data = {
 };
 
 static const struct of_device_id mtmips_of_match[] = {
+	{
+		.compatible = "ralink,rt2880-reset",
+		.data = NULL,
+	},
 	{
 		.compatible = "ralink,rt2880-sysc",
 		.data = &rt2880_clk_data,
@@ -1088,25 +1092,11 @@ static int mtmips_clk_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static const struct of_device_id mtmips_clk_of_match[] = {
-	{ .compatible = "ralink,rt2880-reset" },
-	{ .compatible = "ralink,rt2880-sysc" },
-	{ .compatible = "ralink,rt3050-sysc" },
-	{ .compatible = "ralink,rt3052-sysc" },
-	{ .compatible = "ralink,rt3352-sysc" },
-	{ .compatible = "ralink,rt3883-sysc" },
-	{ .compatible = "ralink,rt5350-sysc" },
-	{ .compatible = "ralink,mt7620-sysc" },
-	{ .compatible = "ralink,mt7628-sysc" },
-	{ .compatible = "ralink,mt7688-sysc" },
-	{}
-};
-
 static struct platform_driver mtmips_clk_driver = {
 	.probe = mtmips_clk_probe,
 	.driver = {
 		.name = "mtmips-clk",
-		.of_match_table = mtmips_clk_of_match,
+		.of_match_table = mtmips_of_match,
 	},
 };