CHROMIUM: MALI: Don't require opp-hz-real when there is a single clock

It does not seem useful to introduce another redudant (and
non-upstream) entry in the device tree, especially if there is
only a single clock.

BUG=b:149806107
TEST=boot kukui

Change-Id: I065126860e03c386a00daff223806a3bceaa2812
Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
diff --git a/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_devfreq.c b/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_devfreq.c
index e42fa23..6e681dd 100644
--- a/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_devfreq.c
+++ b/drivers/gpu/arm/midgard/backend/gpu/mali_kbase_devfreq.c
@@ -432,9 +432,14 @@
 		err = of_property_read_u64(node, "opp-hz-real", real_freqs);
 #endif
 		if (err < 0) {
-			dev_warn(kbdev->dev, "Failed to read opp-hz-real property with error %d\n",
+			if (kbdev->nr_clocks == 1) {
+				/* Single clock, fall back to using opp-hz. */
+				real_freqs[0] = opp_freq;
+			} else {
+				dev_warn(kbdev->dev, "Failed to read opp-hz-real property with error %d\n",
 					err);
-			continue;
+				continue;
+			}
 		}
 #ifdef CONFIG_REGULATOR
 		err = of_property_read_u32_array(node,