OMAP4: DSS2: DSI: Changes for DSI2 on OMAP4

Introduce DSI2 PLL clock sources needed by LCD2 channel and DSI2 Protocol
engine and DISPC Functional clock. Do the following:

- Modify dss_get_dsi_clk_source() and dss_select_dsi_clk_source() to take the
  dsi module number as an argument.
- Create debugfs files for dsi2, split the corresponding debugfs functions.
- Allow DPI to use these new clock sources.

Signed-off-by: Archit Taneja <archit@ti.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

include/video/omapdss.h

@@ -179,6 +179,8 @@ enum omap_dss_clk_source {
 						 * 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 */
 };
 
 /* RFBI */