dts: npcx: Fixed the name of nodes in device-tree files.

Fixed the name of nodes in device-tree files by following rules:

If object is 'phandles', use underscores for object name.
If not, such as 'node' or 'property', use hyphens for object name.

This CL also applies normal style for all nodes in npcx device-tree
files.

Signed-off-by: Mulin Chao <mlchao@nuvoton.com>