gnu: pixman: Enable some features.

* gnu/packages/xdisorg.scm (pixman) [arguments]<#:configure-flags>[--enable-timers]: New flag.
[--enable-gnuplot]: New flag.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

gnu/packages/xdisorg.scm

@@ -522,7 +522,11 @@ following the mouse.")
          "pixman-CVE-2016-5296.patch"))))
     (build-system gnu-build-system)
     (arguments
-     '(#:configure-flags '("--disable-static")))
+     `(#:configure-flags
+       (list
+        "--disable-static"
+        "--enable-timers"
+        "--enable-gnuplot")))
     (native-inputs
      `(("pkg-config" ,pkg-config)))
     (inputs