drivers: clock_control: add support for Nuvoton numaker series CLK

Add Nuvoton numaker series clock controller support, including:
1.  Do system clock initialization in z_arm_platform_init().
2.  Support peripheral clock control API equivalent to BSP
    CLK_EnableModuleClock()/CLK_SetModuleClock().

Signed-off-by: cyliang tw <cyliang@nuvoton.com>