configure: search for lib with clock_getres()

Like clock_gettime(), clock_getres() is in -lrt for glibc < 2.17.
Add a check for it, like is done for clock_gettime().

Fixes:
    http://autobuild.buildroot.net/results/bce/bcecdbbce4a99eb1e9bfbf519857bf94d8952037/

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>
2 files changed