VideoCommon: Move backend_info out of VideoConfig struct.

Source/Core/VideoBackends/Metal/MTLGfx.mm

@@ -334,7 +334,7 @@ void Metal::Gfx::ClearRegion(const MathUtil::Rectangle<int>& target_rc, bool col
             static_cast<double>((color >> 24) & 0xFF) / 255.0);
         // clang-format on
         float z_normalized = static_cast<float>(z & 0xFFFFFF) / 16777216.0f;
-        if (!g_Config.backend_info.bSupportsReversedDepthRange)
+        if (!g_backend_info.bSupportsReversedDepthRange)
           z_normalized = 1.f - z_normalized;
         g_state_tracker->BeginClearRenderPass(clear_color, z_normalized);
         return;