tmf.xml: Fix xml timegraph resolution

tmf.xml: Fix xml timegraph resolution

When the window range is less than the display width, the resolution was
then equal to 0. The time event was not shown until the user change the
zoom level. Now we set the resolution value to 1 instead of 0.

Change-Id: I4f0ae39576c452f0bdfbaf23b836f3af758f0b91
Signed-off-by: Jean-Christian Kouame <jean-christian.kouame@ericsson.com>
Reviewed-on: https://git.eclipse.org/r/87339
Reviewed-by: Hudson CI
Reviewed-by: Matthew Khouzam <matthew.khouzam@ericsson.com>