time: implement ModemTime in ModemBase

Signed-off-by: Thomas Tuttle <ttuttle@chromium.org>
(cherry picked from commit 8121b8e31922e89e5429b8ffa8c388d84f65c1f0)

Conflicts:

	src/mm-modem-base.c

BUG=chromium-os:10366
TEST=Still compiles
CQ-DEPEND=I589d68cce9ff1b13b1713f832d3aac9585eefb12

Change-Id: Ic15187330f7a94efe368b31267d25a5ec89459a1
Reviewed-on: https://gerrit.chromium.org/gerrit/14083
Commit-Ready: ttuttle <ttuttle@chromium.org>
Reviewed-by: ttuttle <ttuttle@chromium.org>
Tested-by: ttuttle <ttuttle@chromium.org>
3 files changed