ffdc: Enable dreport based ffdc debug data collection

Enabled dreport based debug data collection by default
in the ffdc tool.

Added -D option to disable the dreport based data collection
and switch back to ffdc way.

Change-Id: I429533d3d04495ea3cda2bcb2b1090f1d971d530
Signed-off-by: Jayanth Othayoth <ojayanth@in.ibm.com>