devel/msp430-debug-stack: Better devd config installed as sample.

1. Install devd config as sample, to preserve actual config on package removal.
2. Make this config better to support more devices and back-channel UART.

PR: 286020
Reported by: Yusuf Yaman <nxjoseph@protonmail.com> [1]
Reported by: Petre Rodan <petre.rodan@subdimension.ro> [2]