remove references to gordon as it is no longer enabled

libstarpu.pc.in

@@ -26,4 +26,3 @@ Cflags: -I${includedir}/starpu/@STARPU_EFFECTIVE_VERSION@ @STARPU_CUDA_CPPFLAGS@
 Libs: -L${libdir} -lstarpu-@STARPU_EFFECTIVE_VERSION@ @STARPU_OPENCL_LDFLAGS@ @STARPU_CUDA_LDFLAGS@
 Libs.private: @LDFLAGS@ @LIBS@
 Requires: @HWLOC_REQUIRES@
-Requires.private: @GORDON_REQUIRES@

starpu-1.0.pc.in

@@ -32,4 +32,3 @@ Cflags: -I${includedir}/starpu/@STARPU_EFFECTIVE_VERSION@ @STARPU_CUDA_CPPFLAGS@
 Libs: -L${libdir} -lstarpu-@STARPU_EFFECTIVE_VERSION@ @STARPU_CUDA_LDFLAGS@ @STARPU_OPENCL_LDFLAGS@
 Libs.private: @LDFLAGS@ @LIBS@ @LIBSTARPU_LDFLAGS@
 Requires: @HWLOC_REQUIRES@
-Requires.private: @GORDON_REQUIRES@