community/gpsd: depend on loopback initscript
Without this gpsd can start before lo is available, and gpsd's default configuration in Alpine is to bind to lo, so it fails:
2021-03-28 20:01:34 notice gpsd:PROG: control socket opened at /var/run/gpsd.sock
2021-03-28 20:01:34 notice gpsd[1718]: gpsd:INFO: launching (Version 3.22)
2021-03-28 20:01:34 notice gpsd[1718]: gpsd:IO: opening IPv4 socket
2021-03-28 20:01:34 err gpsd[1718]: gpsd:ERROR: can't bind to IPv4 port gpsd, Address not available
2021-03-28 20:01:34 info NetworkManager[1659]: <info> [1616961694.5701] device (wlan0): driver supports Access Point (AP) mode
2021-03-28 20:01:34 notice gpsd[1718]: gpsd:IO: opening IPv6 socket
2021-03-28 20:01:34 err gpsd[1718]: gpsd:ERROR: can't bind to IPv6 port gpsd, Address not available
2021-03-28 20:01:34 err gpsd[1718]: gpsd:ERROR: command sockets creation failed, netlib errors -1, -1