rtapi_math: drop unneeded gcc version check
rtapi_math: drop unneeded gcc version check

As documented at http://wiki.linuxcnc.org/cgi-bin/wiki.pl?MinimumSoftwareVersions
the oldest platform we're likely to target with linuxcnc 2.7 is Ubuntu 10.04
with gcc 4.4.

bmwiedemann/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,bmwiedemann/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror