treewide: use linux/time.h for time conversion defines

Now that we have time conversion defines from in time.h there is no need
for each driver to define their own version.

Signed-off-by: Igor Prusov <ivprusov@salutedevices.com>
Reviewed-by: Svyatoslav Ryhel <clamor95@gmail.com> # tegra
Reviewed-by: Eugen Hristev <eugen.hristev@collabora.com> #at91
Reviewed-by: Caleb Connolly <caleb.connolly@linaro.org> #qcom geni
Reviewed-by: Stefan Bosch <stefan_b@posteo.net> #nanopi2
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>