drm/omap: cleanup dispc_fclk_rate()

With the new PLL helpers, we can clean up the dispc_fclk_rate(). This
will also make dispc_fclk_rate() support clock sources it didn't support
earlier.
Signed-off-by: NTomi Valkeinen <tomi.valkeinen@ti.com>

drivers/gpu/drm/omapdrm/dss/dispc.c

@@ -3299,30 +3299,21 @@ static void dispc_mgr_get_lcd_divisor(enum omap_channel channel, int *lck_div,
 
 static unsigned long dispc_fclk_rate(void)
 {
-	struct dss_pll *pll;
-	unsigned long r = 0;
+	unsigned long r;
+	enum dss_clk_source src;
 
-	switch (dss_get_dispc_clk_source()) {
-	case DSS_CLK_SRC_FCK:
+	src = dss_get_dispc_clk_source();
+
+	if (src == DSS_CLK_SRC_FCK) {
 		r = dss_get_dispc_clk_rate();
-		break;
-	case DSS_CLK_SRC_PLL1_1:
-		pll = dss_pll_find("dsi0");
-		if (!pll)
-			pll = dss_pll_find("video0");
+	} else {
+		struct dss_pll *pll;
+		unsigned clkout_idx;
 
-		r = pll->cinfo.clkout[0];
-		break;
-	case DSS_CLK_SRC_PLL2_1:
-		pll = dss_pll_find("dsi1");
-		if (!pll)
-			pll = dss_pll_find("video1");
+		pll = dss_pll_find_by_src(src);
+		clkout_idx = dss_pll_get_clkout_idx_for_src(src);
 
-		r = pll->cinfo.clkout[0];
-		break;
-	default:
-		BUG();
-		return 0;
+		r = pll->cinfo.clkout[clkout_idx];
 	}
 
 	return r;