package/gpsd: unconditionally enable NTP time hinting support

package/gpsd: unconditionally enable NTP time hinting support

Mandatory LEAP* defines are only enabled when TIMEHINT_ENABLE is
enabled: https://gitlab.com/gpsd/gpsd/blob/master/gpsd.h#L293

And TIMEHINT_ENABLE is only enabled when NTPSHM_ENABLE is enabled:
https://gitlab.com/gpsd/gpsd/blob/master/gpsd.h#L109

Upstream has entirely dropped the TIMEHINT_ENABLE option:

  https://gitlab.com/gpsd/gpsd/commit/8546be5f1eee36fd3fc66f09f2adfc18814d574c

So, for the time being, we simply enable it unconditionally.

Fixes:

  http://autobuild.buildroot.net/results/44639b8fe407bee30ac96ab54b8037439f3dac88/

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
[Thomas: drop Config.in.legacy, improve commit log]
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>