media: omap: allow building it with COMPILE_TEST

Now that we have stubs for omap FB driver, let it build with
COMPILE_TEST.
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/omap/Kconfig

 config VIDEO_OMAP2_VOUT_VRFB
 	bool
+	default y
+	depends on VIDEO_OMAP2_VOUT && (OMAP2_VRFB || COMPILE_TEST)
 
 config VIDEO_OMAP2_VOUT
 	tristate "OMAP2/OMAP3 V4L2-Display driver"
-	depends on MMU
-	depends on ARCH_OMAP2 || ARCH_OMAP3
-	depends on FB_OMAP2
+	depends on MMU && FB_OMAP2
+	depends on ARCH_OMAP2 || ARCH_OMAP3 || COMPILE_TEST
 	select VIDEOBUF_GEN
 	select VIDEOBUF_DMA_CONTIG
 	select OMAP2_VRFB if ARCH_OMAP2 || ARCH_OMAP3
-	select VIDEO_OMAP2_VOUT_VRFB if VIDEO_OMAP2_VOUT && OMAP2_VRFB
 	select FRAME_VECTOR
 	default n
 	---help---