dts: Documentation: Add documentation for Exynos7 SoC thermal bindings

Add documentation for exynos7 thermal bindings including compatible
name and special clock properties.
Acked-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Abhilash Kesavan <a.kesavan@samsung.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

Documentation/devicetree/bindings/thermal/exynos-thermal.txt

@@ -12,6 +12,7 @@
 	       "samsung,exynos5420-tmu-ext-triminfo" for TMU channels 2, 3 and 4
 			Exynos5420 (Must pass triminfo base and triminfo clock)
 	       "samsung,exynos5440-tmu"
+	       "samsung,exynos7-tmu"
 - interrupt-parent : The phandle for the interrupt controller
 - reg : Address range of the thermal registers. For soc's which has multiple
 	instances of TMU and some registers are shared across all TMU's like
@@ -32,10 +33,13 @@
 - clocks : The main clocks for TMU device
 	-- 1. operational clock for TMU channel
 	-- 2. optional clock to access the shared registers of TMU channel
+	-- 3. optional special clock for functional operation
 - clock-names : Thermal system clock name
 	-- "tmu_apbif" operational clock for current TMU channel
 	-- "tmu_triminfo_apbif" clock to access the shared triminfo register
 		for current TMU channel
+	-- "tmu_sclk" clock for functional operation of the current TMU
+		channel
 - vtmu-supply: This entry is optional and provides the regulator node supplying
 		voltage to TMU. If needed this entry can be placed inside
 		board/platform specific dts file.