meson: always probe u2f and canokey if the option is enabled

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/meson.build b/meson.build
index 2133505..7344e36 100644
--- a/meson.build
+++ b/meson.build
@@ -1828,12 +1828,12 @@
                       version: '>=2.5.1', method: 'pkg-config')
 endif
 u2f = not_found
-if have_system
+if not get_option('u2f').auto() or have_system
   u2f = dependency('u2f-emu', required: get_option('u2f'),
                    method: 'pkg-config')
 endif
 canokey = not_found
-if have_system
+if not get_option('canokey').auto() or have_system
   canokey = dependency('canokey-qemu', required: get_option('canokey'),
                    method: 'pkg-config')
 endif