hwc2: Correct frame rate declaration.

Declare proper type for frame rate. In-correct type declaration
is leading to invalid frame rate read from metadata.

Change-Id: I5e7a8dc014d9d070ba447c12db162fb45b3b5ad6
CRs-Fixed: 2086269
diff --git a/sdm/libs/hwc2/hwc_layers.cpp b/sdm/libs/hwc2/hwc_layers.cpp
index 6b5d470..a45fb1f 100644
--- a/sdm/libs/hwc2/hwc_layers.cpp
+++ b/sdm/libs/hwc2/hwc_layers.cpp
@@ -582,7 +582,7 @@
     }
   }
 
-  uint32_t fps = 0;
+  float fps = 0;
   if (getMetaData(handle, GET_REFRESH_RATE  , &fps) == 0) {
     layer->frame_rate = RoundToStandardFPS(fps);
   }