spi: s3c64xx: add exynos5433 spi compatible

The samsung,exynos5433-spi has some peculiarities that bring the
need of creating a new compatible in the binding.

One of those is the 3-clocks controller management where the spi
is fed with three clocks: "spi", "busclkN" and "ioclk".

By adding the exynos5433-spi, we deprecate the exynos7 compatible
and discourage its use.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Reviewed-by: Michael Turquette <mturquette@baylibre.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/spi/spi-samsung.txt

@@ -9,7 +9,8 @@ Required SoC Specific Properties:
     - samsung,s3c2443-spi: for s3c2443, s3c2416 and s3c2450 platforms
     - samsung,s3c6410-spi: for s3c6410 platforms
     - samsung,s5pv210-spi: for s5pv210 and s5pc110 platforms
-    - samsung,exynos7-spi: for exynos7 platforms
+    - samsung,exynos5433-spi: for exynos5433 compatible controllers
+    - samsung,exynos7-spi: for exynos7 platforms <DEPRECATED>
 
 - reg: physical base address of the controller and length of memory mapped
   region.