OMAP: DSS2: Add missing dummy functions

dpi.c does not compile if DSI is not compiled in. Add the missing dummy
functions so that dpi.c compiles.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dss.h b/drivers/video/omap2/dss/dss.h
index 3e6dbd5..ef193750 100644
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -322,6 +322,30 @@
 	WARN("%s: DSI not compiled in, returning rate as 0\n", __func__);
 	return 0;
 }
+static inline int dsi_pll_set_clock_div(struct platform_device *dsidev,
+		struct dsi_clock_info *cinfo)
+{
+	WARN("%s: DSI not compiled in\n", __func__);
+	return -ENODEV;
+}
+static inline int dsi_pll_calc_clock_div_pck(struct platform_device *dsidev,
+		bool is_tft, unsigned long req_pck,
+		struct dsi_clock_info *dsi_cinfo,
+		struct dispc_clock_info *dispc_cinfo)
+{
+	WARN("%s: DSI not compiled in\n", __func__);
+	return -ENODEV;
+}
+static inline int dsi_pll_init(struct platform_device *dsidev,
+		bool enable_hsclk, bool enable_hsdiv)
+{
+	WARN("%s: DSI not compiled in\n", __func__);
+	return -ENODEV;
+}
+static inline void dsi_pll_uninit(struct platform_device *dsidev,
+		bool disconnect_lanes)
+{
+}
 static inline void dsi_wait_pll_hsdiv_dispc_active(struct platform_device *dsidev)
 {
 }