npcx: move scfg driver from pinctrl to soc/arm/nuvoton_npcx/common

In NPCX chips, System Configuration module can configure not only
pinctrl but also misc. functionality such as glue and flash write
protection. This change moves the scfg driver from the pinctrl folder
to soc/arm/nuvoton_npcx/common and renames it to avoid confusion.

Signed-off-by: Jun Lin <CHLin56@nuvoton.com>