drm/tegra: sor - Enable only the necessary number of lanes

Instead of always enabling all four lanes, enable only the number probed
from the link.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/sor.c b/drivers/gpu/drm/tegra/sor.c
index fefd26f0..7d2a5db 100644
--- a/drivers/gpu/drm/tegra/sor.c
+++ b/drivers/gpu/drm/tegra/sor.c
@@ -656,7 +656,7 @@
 
 	value = tegra_sor_readl(sor, SOR_DP_LINKCTL_0);
 	value &= ~SOR_DP_LINKCTL_LANE_COUNT_MASK;
-	value |= SOR_DP_LINKCTL_LANE_COUNT(4);
+	value |= SOR_DP_LINKCTL_LANE_COUNT(link.num_lanes);
 	tegra_sor_writel(sor, value, SOR_DP_LINKCTL_0);
 
 	/* start lane sequencer */