memory: tegra: Fix missed registers values latching

Some of Memory Controller registers are shadowed and require latching in
order to copy assembly state into the active, MC_EMEM_ARB_CFG is one of
these registers.
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/memory/tegra/mc.c

@@ -51,6 +51,9 @@
 #define MC_EMEM_ADR_CFG 0x54
 #define MC_EMEM_ADR_CFG_EMEM_NUMDEV BIT(0)
 
+#define MC_TIMING_CONTROL		0xfc
+#define MC_TIMING_UPDATE		BIT(0)
+
 static const struct of_device_id tegra_mc_of_match[] = {
 #ifdef CONFIG_ARCH_TEGRA_2x_SOC
 	{ .compatible = "nvidia,tegra20-mc-gart", .data = &tegra20_mc_soc },
@@ -301,6 +304,9 @@ static int tegra_mc_setup_latency_allowance(struct tegra_mc *mc)
 		writel(value, mc->regs + la->reg);
 	}
 
+	/* latch new values */
+	writel(MC_TIMING_UPDATE, mc->regs + MC_TIMING_CONTROL);
+
 	return 0;
 }