ARM: dts: Remove duplicated I2C7 nodes in exynos5250-snow

The i2c_7 node (i2c@12CD0000) with LVDS bridge child node was put in
Exynos5250 Snow DTS file twice. Move the LVDS bridge to proper existing
i2c_7 node.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Kukjin Kim <kgene@kernel.org>