clk/exynos5420: add hdmi mux to change parents in hdmi driver

hdmi driver needs to change the parent of hdmi clock
to pixel clock or hdmiphy clock, based on the stability
of hdmiphy. This patch is exposing the mux for changing
the parent.

Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
Acked-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>

Documentation/devicetree/bindings/clock/exynos5420-clock.txt

@@ -182,6 +182,11 @@ clock which they consume.
   g3d			501
   smmu_mixer		502
 
+  Mux			ID
+  ----------------------------
+
+  mout_hdmi		640
+
 Example 1: An example of a clock controller node is listed below.
 
 	clock: clock-controller@0x10010000 {

drivers/clk/samsung/clk-exynos5420.c

@@ -140,6 +140,9 @@ enum exynos5420_clks {
 	aclk333_g2d = 480, g2d, aclk333_432_gscl = 490, smmu_3aa, smmu_fimcl0,
 	smmu_fimcl1, smmu_fimcl3, fimc_lite3, aclk_g3d = 500, g3d, smmu_mixer,
 
+	/* mux clocks */
+	mout_hdmi = 640,
+
 	nr_clks,
 };
 
@@ -400,7 +403,7 @@ static struct samsung_mux_clock exynos5420_mux_clks[] __initdata = {
 	MUX(none, "mout_mipi1", group2_p, SRC_DISP10, 16, 3),
 	MUX(none, "mout_dp1", group2_p, SRC_DISP10, 20, 3),
 	MUX(none, "mout_pixel", group2_p, SRC_DISP10, 24, 3),
-	MUX(none, "mout_hdmi", hdmi_p, SRC_DISP10, 28, 1),
+	MUX(mout_hdmi, "mout_hdmi", hdmi_p, SRC_DISP10, 28, 1),
 
 	/* MAU Block */
 	MUX(none, "mout_maudio0", maudio0_p, SRC_MAU, 28, 3),