[media] omap: be sure that MMU is there for COMPILE_TEST

COMPILE_TEST fail on (some) archs without MMU.
Signed-off-by: NMauro Carvalho Chehab <m.chehab@samsung.com>

drivers/media/platform/omap/Kconfig

@@ -3,7 +3,7 @@ config VIDEO_OMAP2_VOUT_VRFB
 
 config VIDEO_OMAP2_VOUT
 	tristate "OMAP2/OMAP3 V4L2-Display driver"
-	depends on ARCH_OMAP2 || ARCH_OMAP3 || COMPILE_TEST
+	depends on ARCH_OMAP2 || ARCH_OMAP3 || (COMPILE_TEST && HAS_MMU)
 	select VIDEOBUF_GEN
 	select VIDEOBUF_DMA_CONTIG
 	select OMAP2_DSS if HAS_IOMEM && ARCH_OMAP2PLUS