drivers: npcx: replace type of register base address with uintptr_t

Replace npcx register base address type, uint32_t, with uintptr_t.
It is easier to know what type of base address and for linear
addresses treated as integral values.

This CL also modified IS_BIT_SET() macro function to fit MISRA code
guidelines.

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