gpsd: switch to Git snapshot

Since the gpsd version bump from 3.9 to 3.10, gpsd has been generating a lot
of autobuild failures. See, for example, the following.

  http://autobuild.buildroot.net/results/c8f/c8f2eed70cfbdcb7e7af820977aa531b59f0575a/



A 3.11 release is expected shortly; in the interim, switch to a recent Git
snapshot in which the most serious build problems appear to have been fixed.

Signed-off-by: Simon Dawson <spdawson@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>