drm/tegra: Rename host1x_drm structure to tegra_drm

The host1x and Tegra DRM drivers are currently tightly coupled. Renaming
the structure marks the boundary more clearly.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/host1x/dev.c b/drivers/gpu/host1x/dev.c
index 4716302..0f7b44c 100644
--- a/drivers/gpu/host1x/dev.c
+++ b/drivers/gpu/host1x/dev.c
@@ -163,7 +163,7 @@
 
 	host1x_debug_init(host);
 
-	host1x_drm_alloc(pdev);
+	tegra_drm_alloc(pdev);
 
 	return 0;