drivers: pinctrl: mec5: Microchip MEC5 HAL based pinctrl driver

Add a pinctrl driver for Microchip MEC5 HAL based chips.
The driver removes the YAML enum "no change" property
value from the driver strength and slew rate properties.
Update the shared header file in mec soc common folder to
use a different Z_PINCTRL_STATE_PINCFG_INIT for MEC5.
Modifications to legacy MEC172x XEC PINCTRL will be in
a future PR.

Signed-off-by: Scott Worley <scott.worley@microchip.com>