ARM: dts: Add missing aliases entry for i2c-mhl node

ARM: dts: Add missing aliases entry for i2c-mhl node

This fixes regression introduced in commit 10d282f12d57a467a83a
ARM: exynos: dts: cleanup the dts file for trats2

Without an alias the i2c-mhl get dynamically assigned an I2C bus
id 0 which is assigned in DT to the I2C0 hardware controller.
As a result I2C0 hardware controller fails to initialize which
in turn breaks the camera subsystem driver initialization.

Change-Id: I92c254cc1d93899b277761b750b0e657c2daad95
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>