gnu: Add libliftoff.

* gnu/packages/freedesktop.scm (libliftoff): New variable.

Change-Id: I19eda24aea4327bcd72a7e15ec0784ef1e302783
Reviewed-by: Steve George <steve@futurile.net>
Signed-off-by: Andreas Enge <andreas@enge.fr>

gnu/packages/freedesktop.scm

@@ -356,6 +356,30 @@ (define-public libglib-testing
     (home-page "https://gitlab.gnome.org/pwithnall/libglib-testing")
     (license license:lgpl2.1+)))
 
+(define-public libliftoff
+  (package
+    (name "libliftoff")
+    (version "0.5.0")
+    (source (origin
+              (method git-fetch)
+              (uri (git-reference
+                    (url "https://gitlab.freedesktop.org/emersion/libliftoff")
+                    (commit (string-append "v" version))))
+              (file-name (git-file-name name version))
+              (sha256
+               (base32
+                "163g8ndsbma7acy2k9mrnvlpb7yi4431hgkx1gygkafgwpq1ii1x"))))
+    (build-system meson-build-system)
+    (native-inputs (list pkg-config))
+    (inputs (list libdrm))
+    (home-page "https://gitlab.freedesktop.org/emersion/libliftoff")
+    (synopsis "Lightweight KMS plane library for compositors")
+    (description "Libliftoff eases the use of
+@acronym{KMS, Kernel Mode Setting} planes from userspace.  Users create
+\"virtual planes\" called layers, set KMS properties on them, and libliftoff
+will pick hardware planes for these layers if possible.")
+    (license license:expat)))
+
 (define-public malcontent
   (package
     (name "malcontent")