In preparation for the re-introduction of the Exynos4212, move
their shared definitions to a separate file. Rename the pinctrl
definitions accordingly, and adapt the Exynos4412 DTSI to these
changes.

This reverts part of commit bca9085e ("ARM: dts: exynos:
remove Exynos4212 support (dead code)").
Signed-off-by: Artur Weber <aweber.kernel@gmail.com>
Link: https://lore.kernel.org/r/20230501195525.6268-10-aweber.kernel@gmail.comSigned-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>