This patch implements Qemu user mode clock_adjtime() syscall support.

The implementation is based on invocation of host's clock_adjtime().
Signed-off-by: NAleksandar Rikalo <aleksandar.rikalo@imgtec.com>
Signed-off-by: NAleksandar Markovic <aleksandar.markovic@imgtec.com>
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>