f, 0f: print FW_REV as it is done by "s"
 1f:    print FW_STRING1 which should be MREF2LPC
 2f:    print FW_STRING2 which can be R1, R2, R3 or 25_R2
 3f:    print FW_STRING3 which is the version like 20231124
 U:     print uptime like 'S' does for cycles in state

This commit adds commands for the remaining bits of the 's' command
output which do not yet have their own commands. This in turn allows
access to the information of the 's' command without needing to parse
the string returned by 's' which is supposed to be human readable and
can change at any time.