drm: omapdrm: Make fbdev emulation optional

Don't compile the fbdev emulation code when fbdev emulation support is
disabled.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/gpu/drm/omapdrm/Makefile b/drivers/gpu/drm/omapdrm/Makefile
index 778372b..368c1ec 100644
--- a/drivers/gpu/drm/omapdrm/Makefile
+++ b/drivers/gpu/drm/omapdrm/Makefile
@@ -12,10 +12,11 @@
 	omap_encoder.o \
 	omap_connector.o \
 	omap_fb.o \
-	omap_fbdev.o \
 	omap_gem.o \
 	omap_gem_dmabuf.o \
 	omap_dmm_tiler.o \
 	tcm-sita.o
 
+omapdrm-$(CONFIG_DRM_FBDEV_EMULATION) += omap_fbdev.o
+
 obj-$(CONFIG_DRM_OMAP)	+= omapdrm.o