Fix: ITK EXCLUDE_FROM_ALL warning for GPU case.

Signed-off-by: Irina Vidal <irina.vidal-migallon@inria.fr>
COMP: Fix compliler warnings

Also clean up itkYvvWhiteImageTest.cxx to have proper whitespace.
Merge pull request #3 from brianhelba/Warning-Fix

COMP: Fix compliler warnings