arm64: dts: exynos: Enable HS400 mode for eMMC for TM2

TM2 can support the HS400 mode, but eMMC is working in the lowest mode.
This patch adds the properties for HS400 and other modes.

Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>