ARM: shmobile: defconfig: Enable ADV7612 CEC support

Enable support for Consumer Electronics Control on the Analog Devices
ADV7612 HDMI receiver, which is used on the Koelsch and Lager boards.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200624131931.3686-7-geert+renesas@glider.be

arch/arm/configs/shmobile_defconfig

@@ -122,6 +122,7 @@ CONFIG_VIDEO_RENESAS_JPU=y
 CONFIG_VIDEO_RENESAS_VSP1=y
 CONFIG_VIDEO_ADV7180=y
 CONFIG_VIDEO_ADV7604=y
+CONFIG_VIDEO_ADV7604_CEC=y
 CONFIG_VIDEO_ML86V7667=y
 CONFIG_DRM=y
 CONFIG_DRM_RCAR_DU=y