Add universal build_type variant to CMakePackage (#4797)

* Add universal build_type variant to CMakePackage
* Override build_type in some packages with different possible values
* Remove reference to no longer existent debug variant
* Update CBTF packages with new build_type variant
* Keep note on build size of LLVM

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

@@ -83,6 +83,8 @@ class Openspeedshop(CMakePackage):
     variant('rtfe', default=False,
             description="build for clusters heterogeneous processors \
                          on fe/be nodes.")
+    variant('build_type', default='None', values=('None'),
+            description='CMake build type')
 
     # MPI variants
     variant('openmpi', default=False,
@@ -144,9 +146,6 @@ class Openspeedshop(CMakePackage):
 
     build_directory = 'build_openspeedshop'
 
-    def build_type(self):
-        return 'None'
-
     def cmake_args(self):
         spec = self.spec
         compile_flags = "-O2 -g"