dts: microchip: Remove deleted property

PR https://github.com/zephyrproject-rtos/zephyr/pull/55129

 deleted the
"port-sel" property.  Delete this property from remaining Microchip SoC
variants and boards.

Test: west build -b mec172xevb_assy6906 samples/drivers/espi/

Signed-off-by: Keith Short <keithshort@google.com>