Ghost as cuda package (#7501)

* add headers  property to netlib-lapack and intel-mkl

* ghost: fix finding cblas header and libs (at least for mkl and netlib-lapack, which provide headers())

* fix flake8 errors

* ghost: remove unnecessary query parameter

* fix flake8 errors

* ghost: make it a CudaPackage (as suggested by @davydden, thanks!)

* ghost: missing whitespace

var/spack/repos/builtin/packages/netlib-lapack/package.py

@@ -48,7 +48,8 @@ class NetlibLapack(Package):
     version('3.4.0', '02d5706ec03ba885fc246e5fa10d8c70')
     version('3.3.1', 'd0d533ec9a5b74933c2a1e84eedc58b4')
 
-    variant('debug', default=False, description='Activates the Debug build type')
+    variant('debug', default=False,
+            description='Activates the Debug build type')
     variant('shared', default=True, description="Build shared library version")
     variant('external-blas', default=False,
             description='Build lapack with an external blas')
@@ -123,6 +124,13 @@ def lapack_libs(self):
             libraries, root=self.prefix, shared=shared, recursive=True
         )
 
+    @property
+    def headers(self):
+        include_dir = self.spec.prefix.include
+        cblas_h = join_path(include_dir, 'cblas.h')
+        lapacke_h = join_path(include_dir, 'lapacke.h')
+        return HeaderList([cblas_h, lapacke_h])
+
     def install_one(self, spec, prefix, shared):
         cmake_args = [
             '-DBUILD_SHARED_LIBS:BOOL=%s' % ('ON' if shared else 'OFF'),