ARM: dts: exynos: drop unused pinctrl defines in Exynos3250

The PIN_OUT/PIN_OUT_SET/PIN_CFG defines for pin controller pin
configuration are not used.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20220111201426.326777-4-krzysztof.kozlowski@canonical.com