build: only add dependency for valgrind supported hosts

build: only add dependency for valgrind supported hosts

Windows is confused with implicit .exe suffix ie:

  scons: *** [out\windows\...\utresource\csdk\connectivity\test\catests] \
  Explicit dependency ...\utresource\csdk\connectivity\test\catests' \
  not found, needed by target \
  ...

Change-Id: I010eb13f7904cba510e492b73be1caeeb0061edd
Signed-off-by: Philippe Coval <philippe.coval@osg.samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/14849
Reviewed-by: Ziran Sun <ziran.sun@samsung.com>
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>