Add packageconfig to keep only the ublox tool.
Missing files if this config is applied are:
- firmware itself (UBX_M8_301_ADR_421_NEO_M8L.bin)
- map of the flash (ubx-fw-flash.xml)
- wrapper to flash the modem easily (gnss-fw-update)
BugzID: 60600
Signed-off-by: Patrick Zysset <patrick.zysset@netmodule.com>