drm/omap: copy enum omap_dss_clk_source

At the moment 'enum omap_dss_clk_source' is in omapdss.h, shared by
omapdrm and omapfb. We're about to improve the omapdrm clock code, so we
need to make a separate copy of the enum for each driver.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
diff --git a/drivers/gpu/drm/omapdrm/dss/dss.h b/drivers/gpu/drm/omapdrm/dss/dss.h
index 38e6ab5..c35245c 100644
--- a/drivers/gpu/drm/omapdrm/dss/dss.h
+++ b/drivers/gpu/drm/omapdrm/dss/dss.h
@@ -102,6 +102,17 @@
 	DSS_WB_LCD3_MGR =	7,
 };
 
+enum omap_dss_clk_source {
+	OMAP_DSS_CLK_SRC_FCK = 0,		/* OMAP2/3: DSS1_ALWON_FCLK
+						 * OMAP4: DSS_FCLK */
+	OMAP_DSS_CLK_SRC_DSI_PLL_HSDIV_DISPC,	/* OMAP3: DSI1_PLL_FCLK
+						 * OMAP4: PLL1_CLK1 */
+	OMAP_DSS_CLK_SRC_DSI_PLL_HSDIV_DSI,	/* OMAP3: DSI2_PLL_FCLK
+						 * OMAP4: PLL1_CLK2 */
+	OMAP_DSS_CLK_SRC_DSI2_PLL_HSDIV_DISPC,	/* OMAP4: PLL2_CLK1 */
+	OMAP_DSS_CLK_SRC_DSI2_PLL_HSDIV_DSI,	/* OMAP4: PLL2_CLK2 */
+};
+
 enum dss_pll_id {
 	DSS_PLL_DSI1,
 	DSS_PLL_DSI2,