gnu: spice-gtk: Propagate required inputs.

* gnu/packages/spice.scm (spice-gtk)[inputs]: Move GTK+, PIXMAN and OPENSSL ...
[propagated-inputs]: ... here.
(virt-viewer)[inputs]: Remove OPENSSL.

gnu/packages/spice.scm

@@ -134,20 +134,22 @@ (define-public spice-gtk
         ("gst-plugins-good" ,gst-plugins-good)
         ("gst-plugins-bad" ,gst-plugins-bad)
         ("gst-plugins-ugly" ,gst-plugins-ugly)
-        ("spice-protocol" ,spice-protocol)))
+        ("spice-protocol" ,spice-protocol)
+
+        ;; These are required by the pkg-config files.
+        ("gtk+" ,gtk+)
+        ("pixman" ,pixman)
+        ("openssl" ,openssl)))
     (inputs
       `(("glib-networking" ,glib-networking)
         ("gobject-introspection" ,gobject-introspection)
-        ("gtk+" ,gtk+)
         ("libepoxy" ,libepoxy)
         ("libjpeg" ,libjpeg)
         ("libxcb" ,libxcb)
         ("lz4" ,lz4)
         ("mesa" ,mesa)
-        ("pixman" ,pixman)
         ("pulseaudio" ,pulseaudio)
         ("python" ,python)
-        ("openssl" ,openssl)
         ("opus" ,opus)
         ("usbredir" ,usbredir)))
     (native-inputs
@@ -291,7 +293,6 @@ (define-public virt-viewer
       `(("gtk+" ,gtk+)
         ("libcap" ,libcap)
         ("libxml2" ,libxml2)
-        ("openssl" ,openssl)
         ("spice-gtk" ,spice-gtk)))
     (native-inputs
       `(("glib:bin" ,glib "bin")