OPP: Allow config_clks helper for single clk case

There is a corner case with Tegra30, where we want to skip clk
configuration via dev_pm_opp_set_opp(), but still want the OPP core to
read the "opp-hz" property so we can find the right OPP via freq finding
helpers.

This is the easiest of the ways to make it work, without any special
hacks in the OPP core. Allow config_clks to be passed for single clk
case.
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

drivers/opp/core.c

@@ -2191,7 +2191,7 @@ static int _opp_set_clknames(struct opp_table *opp_table, struct device *dev,
 		count = 1;
 
 	/* Fail early for invalid configurations */
-	if (!count || (config_clks && count == 1) || (!config_clks && count > 1))
+	if (!count || (!config_clks && count > 1))
 		return -EINVAL;
 
 	/* Another CPU that shares the OPP table has set the clkname ? */
@@ -2217,10 +2217,12 @@ static int _opp_set_clknames(struct opp_table *opp_table, struct device *dev,
 	}
 
 	opp_table->clk_count = count;
+	opp_table->config_clks = config_clks;
 
 	/* Set generic single clk set here */
 	if (count == 1) {
-		opp_table->config_clks = _opp_config_clk_single;
+		if (!opp_table->config_clks)
+			opp_table->config_clks = _opp_config_clk_single;
 
 		/*
 		 * We could have just dropped the "clk" field and used "clks"
@@ -2235,8 +2237,6 @@ static int _opp_set_clknames(struct opp_table *opp_table, struct device *dev,
 		 * too.
 		 */
 		opp_table->clk = opp_table->clks[0];
-	} else {
-		opp_table->config_clks = config_clks;
 	}
 
 	return 0;