ARM: dts: exynos: Update maximum frequency for eMMC to 200MHz on Odroid XU3/XU4

Set the eMMC max-frequency to 200MHz for optimal performance on Odroid
XU3/XU4 family of boards.

Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>