Fix pkgconfig dependencies (#11864)

pkgconfig is the correct virtual dependency.

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

@@ -15,7 +15,7 @@ class Clamav(AutotoolsPackage):
 
     version('0.101.2', sha256='0a12ebdf6ff7a74c0bde2bdc2b55cae33449e6dd953ec90824a9e01291277634')
 
-    depends_on('pkg-config', type='build')
+    depends_on('pkgconfig', type='build')
     depends_on('json-c')
     depends_on('openssl')
     depends_on('pcre')

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

@@ -19,7 +19,7 @@ class Launchmon(AutotoolsPackage):
     depends_on('autoconf', type='build', when='@master')
     depends_on('automake', type='build', when='@master')
     depends_on('libtool', type='build', when='@master')
-    depends_on('pkg-config', type='build')
+    depends_on('pkgconfig', type='build')
     depends_on('libgcrypt')
     depends_on('libgpg-error')
     depends_on("elf", type='link')