ARM: shmobile: defconfig: Enable SII902X

The iwg23s board comes with the SiI9022ACNU HDMI transmitter,
this patch makes sure the corresponding driver gets built.
Signed-off-by: Fabrizio Castro <fabrizio.castro@bp.renesas.com>
Reviewed-by: Biju Das <biju.das@bp.renesas.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

arch/arm/configs/shmobile_defconfig

@@ -142,6 +142,7 @@ CONFIG_DRM=y
 CONFIG_DRM_RCAR_DU=y
 CONFIG_DRM_RCAR_LVDS=y
 CONFIG_DRM_DUMB_VGA_DAC=y
+CONFIG_DRM_SII902X=y
 CONFIG_DRM_I2C_ADV7511=y
 CONFIG_DRM_I2C_ADV7511_AUDIO=y
 CONFIG_FB_SH_MOBILE_LCDC=y