drivers: px4io add 'support' command and update rcS logic

[AlexKlimaj]

This PR adds a "supported" command to the px4io driver. If its not supported, then rcS won't attempt to update the IO MCU and start it.

Fixes #22356

[davids5]

@AlexKlimaj

I think all you need is

if px4io supported
then
...
fi

iff --git a/src/drivers/px4io/px4io.cpp b/src/drivers/px4io/px4io.cpp
index 3e24fc48ba..e3d88864cb 100644
--- a/src/drivers/px4io/px4io.cpp
+++ b/src/drivers/px4io/px4io.cpp
@@ -1556,6 +1556,10 @@ int PX4IO::custom_command(int argc, char *argv[])
{
const char *verb = argv[0];

• if (!strcmp(verb, "supported")) {

•  return 0;
  

• }

[davids5]

@AlexKlimaj have a look at 6372bec

[bresch]

This works on my Pixhawk4 mini (at least it doesn't beep anymore).

[davids5]

LGTM we could soften https://github.com/PX4/PX4-Autopilot/pull/22368/files#diff-ff52cb1224c92cc672316dab2f93a98e7db09fb08ccdfbb9fb0015e8d86f1387L1764 to a warning or info

[AlexKlimaj]

LGTM we could soften https://github.com/PX4/PX4-Autopilot/pull/22368/files#diff-ff52cb1224c92cc672316dab2f93a98e7db09fb08ccdfbb9fb0015e8d86f1387L1764 to a warning or info

Changed to INFO. Really shouldn't be an error or warning if its expected to not be there. It should be a warning if it should be there and fails to update or start.