drm/omap: rename dss_clk_source enums

The names of the enum dss_clk_source's values are legacy names, only
correct for OMAP3 DSS. Rename the names to more generic ones.

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 5c54c9a..56c2d27 100644
--- a/drivers/gpu/drm/omapdrm/dss/dss.h
+++ b/drivers/gpu/drm/omapdrm/dss/dss.h
@@ -103,14 +103,13 @@
 };
 
 enum 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 */
+	DSS_CLK_SRC_FCK = 0,
+
+	DSS_CLK_SRC_PLL1_1,
+	DSS_CLK_SRC_PLL1_2,
+
+	DSS_CLK_SRC_PLL2_1,
+	DSS_CLK_SRC_PLL2_2,
 };
 
 enum dss_pll_id {