OMAPDSS: don't WARN if there's no DSI device

dsi_get_dsidev_from_id() gives a WARN if DSI support is not compiled in.
This warning is not right, as it's valid to call
dsi_get_dsidev_from_id() to see if there is DSI support or not.

Remove the WARN().
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

drivers/video/omap2/dss/dss.h

@@ -382,8 +382,6 @@ static inline void dsi_wait_pll_hsdiv_dsi_active(struct platform_device *dsidev)
 }
 static inline struct platform_device *dsi_get_dsidev_from_id(int module)
 {
-	WARN("%s: DSI not compiled in, returning platform device as NULL\n",
-			__func__);
 	return NULL;
 }
 #endif