opencl: autotools: Fix linking order for OpenCL target

Otherwise the build fails with an undefined reference to
clang::FrontendTimesIsEnabled.

Bugzilla: https://bugs.freedesktop.org/106209


Cc: Jan Vesely <jan.vesely@rutgers.edu>
Cc: mesa-stable@lists.freedesktop.org
Signed-off-by: Kai Wasserbäch <kai@dev.carbon-project.org>
Acked-by: Jan Vesely <jan.vesely@rutgers.edu>
Tested-by: Aaron Watry <awatry@gmail.com>
Tested-by: Dieter Nützel <Dieter@nuetzel-hh.de>
(cherry picked from commit b691d919)