hw/mcu/dialog: Keep GPIO mux powered if non-GPIO pins enabled

[andrzej-kaczmarek]

If any pin has non-GPIO function we should not allow PD_COM to be disabled since this will also reset GPIO mux settings and this can lead to unpredictable behavior.

However, if there are no pins configured or all of them are used as standard GPIO, we can just latch their state and disable PD_COM safely.

[apache-mynewt-bot]

Style check summary

No suggestions at this time!