ARM: dts: exynos: Silence i2c-gpio dtschema warning in Galaxy I9100

The name of I2C controller over GPIO lines node ends with '-gpio' which
confuses dtschema:

  /arch/arm/boot/dts/exynos4210-i9100.dt.yaml: /: i2c-gpio:
    {'compatible': ['i2c-gpio'], ...  'maxim,over-volt': [[4500]]}} is not of type 'array'
    From schema: lib/python3.6/site-packages/dtschema/schemas/gpio/gpio-consumer.yaml

Add a '-0' suffix to silence it.  This pattern on naming i2c-gpio is
already present in many other dts.  No functional change.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20200830135200.24304-1-krzk@kernel.org