thermal: exynos: Document compatible for Exynos5433 TMU

Commit 488c7455 ("thermal: exynos: Add the support for Exynos5433
TMU") added new compatible but forgot to update documentation.
Acked-by: NRob Herring <robh@kernel.org>
Reviewed-by: NChanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: NEduardo Valentin <edubezval@gmail.com>

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

@@ -11,6 +11,7 @@
 	       "samsung,exynos5420-tmu" for TMU channel 0, 1 on Exynos5420
 	       "samsung,exynos5420-tmu-ext-triminfo" for TMU channels 2, 3 and 4
 			Exynos5420 (Must pass triminfo base and triminfo clock)
+               "samsung,exynos5433-tmu"
 	       "samsung,exynos5440-tmu"
 	       "samsung,exynos7-tmu"
 - interrupt-parent : The phandle for the interrupt controller