driver: npcx: add glue module support in npcx series.

The System Glue module includes the three major functions:
— Power Switch Logic (PSL)
— SMBus multi-bus, wake-up support
— Simple Debug Port (SDP)

In NPCX7 series, the SMB5 and SMB6 modules contain a two-way switch to
support two separate SMBus/I2C buses (ports) with one SMB module
(controller). Since a single SMB module is able to serve only one
SMBus/I2C bus at a time, SMB_SEL registerin Glue module is used to
control theconnection of I2Cn_0 and I2Cn_1 interface pins to the SMBn
module (where n is 5, 6).

This CL provides a soc specific pin-control function called
"soc_pinctrl_i2c_port_sel" to switch buses (port) of the same SMB module
(controller). It will be used in the following i2c driver.

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