Fix reset value

In addition to resetting all values set by the user, reset value was also
resetting internal configuration. It resulted that the src mac address
in the outgoing packet was set to whatever was specified in pkt inline,
which is wrong (by default src mac address should be set the the port mac address).
Note that reset value reset any "set values" but does not reset
the packet size.

Change-Id: I9d1cd92be9f5814bd7b104932dd6ffe5df3b6edd
Signed-off-by: Xavier Simonart <xavier.simonart@intel.com>