arm64: dts: exynos: configure GSCALER related clocks on TM2

GSCALER should be feed with clock at certain rates.  Configure it on
Exynos5433 based TM2 board.

Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>