Revert "scripts: Remove dependency on NET"
Revert "scripts: Remove dependency on NET"

This reverts commit 356acc82ad413dfec8d49745793e94a2e2f4c69e.

Conflicts:
* scripts/generate_errors.pl: a line adjacent to a changed line has
  independently changed in the meantime. Just revert the change done
  in the commit that's being reverted.

NXPmicro/mbedtls,Mbed-TLS/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls