Omit "byteswap.h" from pre-configured OMK Linux build.

Omit "byteswap.h" from pre-configured OMK Linux build.

The CDR and rest of the ORTE code uses open-codded ORTE provided
rtps_byteswap function. Build environment provided byteswap
functions are not utilized in the actual ORTE setups.
They could result in better optimized code in future but
attempt to include "byteswap.h" is  probably the last blocker
to use Linux pre-configured ORTE on RTEMS, BSD and BlackBerry.
So comment out HAVE_BYTESWAP_H for now.

Signed-off-by: Pavel Pisa <pisa@cmp.felk.cvut.cz>