ARM: dts: exynos: Add missing CPUs in cooling maps for Odroid X2

While updating cooling maps, the exynos4412-prime.dtsi was left
untouched.  This is not a problem with Odroid U3 because it uses its own
map with fan (which was updated).  However the cooling maps of Odroid X2
rely only on exynos4412-prime.dtsi.

Signed-off-by: Markus Reichl <m.reichl@fivetechno.de>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>