dt-bindings: i2c: exynos5: Add exynosautov9-hsi2c compatible

This patch adds new "samsung,exynosautov9-hsi2c" compatible.
It is for i2c compatible with HSI2C available on Exynos SoC with USI.

Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wolfram Sang <wsa@kernel.org>