drm/tegra: Move driver to DRM tree

In order to make subsystem-wide changes easier, move the Tegra DRM
driver back into the DRM tree.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index f089adf..e39cd03 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -55,4 +55,5 @@
 obj-$(CONFIG_DRM_TILCDC)	+= tilcdc/
 obj-$(CONFIG_DRM_QXL) += qxl/
 obj-$(CONFIG_DRM_MSM) += msm/
+obj-$(CONFIG_DRM_TEGRA) += tegra/
 obj-y			+= i2c/