drm/imx: compile test fixes

- Fix COMPILE_TEST builds with CONFIG_OF disabled.
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Merge tag 'imx-drm-next-2021-01-08' of git://git.pengutronix.de/git/pza/linux into drm-next

drm/imx: compile test fixes

- Fix COMPILE_TEST builds with CONFIG_OF disabled.

Signed-off-by: Dave Airlie <airlied@redhat.com>

From: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://patchwork.freedesktop.org/patch/msgid/8c048f3677f706de306c19ecf6868c4109c1c40d.camel@pengutronix.de

drivers/gpu/drm/imx/Kconfig

@@ -37,7 +37,7 @@ config DRM_IMX_LDB
 config DRM_IMX_HDMI
 	tristate "Freescale i.MX DRM HDMI"
 	select DRM_DW_HDMI
-	depends on DRM_IMX
+	depends on DRM_IMX && OF
 	help
 	  Choose this if you want to use HDMI on i.MX6.
 

include/drm/drm_modes.h

@@ -461,9 +461,19 @@ void drm_display_mode_from_videomode(const struct videomode *vm,
 void drm_display_mode_to_videomode(const struct drm_display_mode *dmode,
 				   struct videomode *vm);
 void drm_bus_flags_from_videomode(const struct videomode *vm, u32 *bus_flags);
+
+#if defined(CONFIG_OF)
 int of_get_drm_display_mode(struct device_node *np,
 			    struct drm_display_mode *dmode, u32 *bus_flags,
 			    int index);
+#else
+static inline int of_get_drm_display_mode(struct device_node *np,
+					  struct drm_display_mode *dmode,
+					  u32 *bus_flags, int index)
+{
+	return -EINVAL;
+}
+#endif
 
 void drm_mode_set_name(struct drm_display_mode *mode);
 int drm_mode_vrefresh(const struct drm_display_mode *mode);