VideoCommon:FramebufferManager: Mark cache as valid after refresh

Otherwise we might never hit the early return
if either depth or color doesnt have any active
tiles.

Source/Core/VideoCommon/FramebufferManager.cpp

@@ -493,6 +493,9 @@ void FramebufferManager::RefreshPeekCache()
         flush_command_buffer = true;
       }
     }
+
+    m_efb_depth_cache.valid = true;
+    m_efb_color_cache.valid = true;
   }
   else
   {