OMAP: DSS2: add dss_get_hdmi_venc_clk_source()

Add dss_get_hdmi_venc_clk_source(), which can be used to get the value
programmed with dss_select_hdmi_venc_clk_source(). This can be used to
find out if the digit output is going to VENC or HDMI.

For OMAP2/3 dss_get_hdmi_venc_clk_source() always returns
DSS_VENC_TV_CLK.

Cc: Mythri P K <mythripk@ti.com>
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 d790580..48bba53 100644
--- a/drivers/video/omap2/dss/dss.h
+++ b/drivers/video/omap2/dss/dss.h
@@ -205,6 +205,7 @@
 void dss_runtime_put(void);
 
 void dss_select_hdmi_venc_clk_source(enum dss_hdmi_venc_clk_source_select);
+enum dss_hdmi_venc_clk_source_select dss_get_hdmi_venc_clk_source(void);
 const char *dss_get_generic_clk_source_name(enum omap_dss_clk_source clk_src);
 void dss_dump_clocks(struct seq_file *s);