Support minute and hour as time suffixes

utils_parse_time_suffix now support the following suffix:

    "us" for microsecond,
    "ms" for millisecond,
    "s"  for second,
    "m"  for minute,
    "h"  for hour

This removes the use of "m" for milliseconds and "u" for microseconds.

Signed-off-by: Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>