drm/tegra: Use fbdev DMA helpers

Use fbdev's DMA helpers for fbdev emulation. They are equivalent to the
previously used system-memory helpers, so no functional changes here.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230707083422.18691-4-tzimmermann@suse.de

drivers/gpu/drm/tegra/Kconfig

@@ -12,7 +12,7 @@ config DRM_TEGRA
 	select DRM_KMS_HELPER
 	select DRM_MIPI_DSI
 	select DRM_PANEL
-	select FB_SYS_HELPERS if DRM_FBDEV_EMULATION
+	select FB_DMA_HELPERS if DRM_FBDEV_EMULATION
 	select TEGRA_HOST1X
 	select INTERCONNECT
 	select IOMMU_IOVA

drivers/gpu/drm/tegra/fbdev.c

@@ -59,9 +59,9 @@ static void tegra_fbdev_fb_destroy(struct fb_info *info)
 
 static const struct fb_ops tegra_fb_ops = {
 	.owner = THIS_MODULE,
-	__FB_DEFAULT_SYS_OPS_RDWR,
+	__FB_DEFAULT_DMA_OPS_RDWR,
 	DRM_FB_HELPER_DEFAULT_OPS,
-	__FB_DEFAULT_SYS_OPS_DRAW,
+	__FB_DEFAULT_DMA_OPS_DRAW,
 	.fb_mmap = tegra_fb_mmap,
 	.fb_destroy = tegra_fbdev_fb_destroy,
 };