libfabric: Add CUDA variant (#46203)

Signed-off-by: Jack Morrison <jack.morrison@cornelisnetworks.com>

var/spack/repos/builtin/packages/libfabric/package.py

@@ -10,7 +10,7 @@
 from spack.package import *
 
 
-class Libfabric(AutotoolsPackage):
+class Libfabric(AutotoolsPackage, CudaPackage):
     """The Open Fabrics Interfaces (OFI) is a framework focused on exporting
     fabric communication services to applications."""
 
@@ -211,6 +211,9 @@ def configure_args(self):
             else:
                 args.append("--enable-{0}=no".format(fabric))
 
+        if self.spec.satisfies("+cuda"):
+            args.append(f"--with-cuda={self.spec['cuda'].prefix}")
+
         return args
 
     def installcheck(self):