add support for RPI CM4

[mbz4]

• more compact & robust
• can attach custom antenna (incl. patch antenna) in case native one insufficient
• has onboard emmc storage up to 32GB
• socketable SoM solution
• excellent hardware support package (cad files & schematics + docs & wiki + forums)
• accepted industry solution
• natively compatible w/ sarakit
• CM5 rumored on horizon, likely using same connection solution (revers compat not guaranteed tho)

https://raspberrypi.dk/en/product/cm4108032-sc0678/

best config spec:
CM4108032 – Raspberry Pi Compute Module 4 – WiFi – 8GB RAM – 32GB Storage

cm4:

sarakit:

[mbz4]

on the dk site cm4 config ~112eur + shipping
very limited availability