ARM: dts: rename alias for i2c_ak8975 label for exynos4412-trats2

The i2c_ak8975 controller uses label i2c8.
This alias is already used for I2C controller 8 defined
in file arch/arm/boot/dts/exynos4.dtsi.

This patch renames a label for i2c_ak8975 to i2c9.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>