libdrm: Update version from 2.4.77 to 2.4.81

[Announcement for 2.4.78 from Apr 7th, 2017][1]:

> This libdrm-2.4.78 fixes some minor cosmetics, a build issue for
> GNU/kFreeBSD, and adds a new page_flip_handler2 event handler, which
> when run on a suitably capable kernel, can provide the CRTC ID to
> userspace for atomic completion events.

[Announcement for 2.4.79 from Apr 8th, 2017][2]:

> Marek Olšák (1):
>       configure.ac: bump version for release
>
> Samuel Pitoiset (1):
>       amdgpu: allow to query GPU sensor related information

[Announcement for 2.4.80 from Apr 14th, 2017][3]:

> Christian Gmeiner (1):
>       configure.ac: bump version for release
>
> Eric Engestrom (1):
>       intel: remove dead code
>
> Philipp Zabel (2):
>       etnaviv: sync uapi header
>       etnaviv: add fence fd support
>
> Tobias Jakobi (1):
>       exynos: add C++ support to exynos_drmif header

[Announcement for 2.4.81 from May 24th, 2017][4]:

> Adam Jackson (3):
>       Export drmDevicesEqual
>       configure: Fix the <sys/sysmacros.h> check
>       Fix stray caller of drmCompareDevices
>
> Edward O'Callaghan (2):
>       amdgpu/: concisely && consistently check null ptrs in canonical form
>       amdgpu: Use the canonical form in branch predicate
>
> Eric Anholt (2):
>       Add pl111 as a KMS driver for utils.
>       Add the DPI encoder/connector types to KMS utils.
>
> Hawking Zhang (1):
>       amdgpu: add raven family id
>
> Ilia Mirkin (1):
>       modetest: fix printing of fourcc on BE machines
>
> Leo Liu (2):
>       amdgpu/drm: add AMDGPU_HW_IP_VCN_DEC
>       amdgpu/drm: add AMDGPU_HW_IP_VCN_ENC
>
> Marek Olšák (1):
>       Bump version to 2.4.81
>
> Nicolai Hähnle (3):
>       amdgpu: add the interface of waiting multiple fences
>       amdgpu: add a test for amdgpu_cs_wait_fences
>       amdgpu: add missing extern "C" headers
>
> Rob Clark (1):
>       freedreno: fix double-free on exit

[1]: https://lists.freedesktop.org/archives/dri-devel/2017-April/138416.html
[2]: https://lists.freedesktop.org/archives/dri-devel/2017-April/138561.html
[3]: https://lists.freedesktop.org/archives/dri-devel/2017-April/139263.html
[4]: https://lists.freedesktop.org/archives/dri-devel/2017-May/142708.html

libdrm.be0

@@ -1,6 +1,6 @@
 #!/usr/bin/env beesh
 
-# BEE_VERSION libdrm-2.4.77-0
+# BEE_VERSION libdrm-2.4.81-0
 
 ## this file was created by bee init and should be executed to build a
 ## bee-package. (Additional hints are located at the end of this file.)