dt-bindings: soc: samsung: exynos-usi: Drop unnecessary status from example

dt-bindings: soc: samsung: exynos-usi: Drop unnecessary status from example

Device nodes in the examples are supposed to be enabled, so the schema
will be validated against them.  Keeping them disabled hides potential
errors.  Only one child of Samsung Exynos USI device node should be
enabled.  The node in the example already selected 'USI_MODE_UART', so
enable the serial node while keeping second - I2C - disabled.

Link: https://lore.kernel.org/r/20250307081341.35197-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>