meson: do not unnecessarily use cmake for dependencies

Both gvnc and sysprof-capture come with pkg-config files, so specify
the method to find them.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tests/migration/meson.build

-sysprof = dependency('sysprof-capture-4', required: false)
+sysprof = dependency('sysprof-capture-4', method: 'pkg-config', required: false)
 glib_static = dependency('glib-2.0', version: glib_req_ver, required: false,
                          method: 'pkg-config', static: true)
 

tests/qtest/meson.build

@@ -321,7 +321,7 @@ qtests = {
 }
 
 if vnc.found()
-  gvnc = dependency('gvnc-1.0', required: false)
+  gvnc = dependency('gvnc-1.0', method: 'pkg-config', required: false)
   if gvnc.found()
     qtests += {'vnc-display-test': [gvnc]}
     qtests_generic += [ 'vnc-display-test' ]