arm64: dts: exynos: gs101: Change labels to lower-case

arm64: dts: exynos: gs101: Change labels to lower-case

DTS coding style expects labels to be lowercase.  No functional impact.
Verified with comparing decompiled DTB (dtx_diff and fdtdump+diff).

Reviewed-by: André Draszik <andre.draszik@linaro.org>
Reviewed-by: Peter Griffin <peter.griffin@linaro.org>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20250219085726.70824-1-krzysztof.kozlowski@linaro.org
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>