OMAP2PLUS: DSS2: Change enum "dss_clk_source" to "omap_dss_clk_source"

Change enum dss_clk_source to omap_dss_clock_source and move it to
'plat/display.h'. Change the enum members to attach "OMAP_" in the beginning.
These changes are done in order to specify the clock sources for DSS in the
board file.

Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/video/omap2/dss/dpi.c b/drivers/video/omap2/dss/dpi.c
index 8ed86f8..47c8a9d 100644
--- a/drivers/video/omap2/dss/dpi.c
+++ b/drivers/video/omap2/dss/dpi.c
@@ -57,7 +57,7 @@
 	if (r)
 		return r;
 
-	dss_select_dispc_clk_source(DSS_CLK_SRC_DSI_PLL_HSDIV_DISPC);
+	dss_select_dispc_clk_source(OMAP_DSS_CLK_SRC_DSI_PLL_HSDIV_DISPC);
 
 	r = dispc_set_clock_div(dssdev->manager->id, &dispc_cinfo);
 	if (r)
@@ -217,7 +217,7 @@
 	dssdev->manager->disable(dssdev->manager);
 
 #ifdef CONFIG_OMAP2_DSS_USE_DSI_PLL
-	dss_select_dispc_clk_source(DSS_CLK_SRC_FCK);
+	dss_select_dispc_clk_source(OMAP_DSS_CLK_SRC_FCK);
 	dsi_pll_uninit();
 	dss_clk_disable(DSS_CLK_SYSCK);
 #endif