drm/tegra: Properly align stride for framebuffers

Tegra20 and Tegra30 both required the buffer line stride to be aligned
on 8 byte boundaries. Tegra114 and Tegra124 increased the alignment to
64 bytes. Introduce a parameter to specify the alignment requirements
for each display controller and round up the pitch of newly allocated
framebuffers appropriately.

Originally-by: Stéphane Marchesin <marcheu@chromium.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/gpu/drm/tegra/drm.h

@@ -45,6 +45,8 @@ struct tegra_drm {
 #ifdef CONFIG_DRM_TEGRA_FBDEV
 	struct tegra_fbdev *fbdev;
 #endif
+
+	unsigned int pitch_align;
 };
 
 struct tegra_drm_client;