package/mesa3d: add support for Intel Vulkan driver

The Vulkan intel driver depends on the i965 dri driver:
https://cgit.freedesktop.org/mesa/mesa/tree/configure.ac?h=12.0#n1653

and a sha1 implementation:
https://cgit.freedesktop.org/mesa/mesa/tree/configure.ac?h=12.0#n1656

The Vulkan driver needs linux/memfd.h
https://cgit.freedesktop.org/mesa/mesa/tree/src/intel/vulkan/anv_allocator.c?h=12.0#n30
which is not available in kernel headers older than 3.18:
https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/log/include/uapi/linux/memfd.h?id=refs/tags/v3.18.36

The Vulkan driver makes use of ifunc
https://cgit.freedesktop.org/mesa/mesa/tree/src/intel/vulkan/anv_entrypoints_gen.py?h=12.0#n287
which is not available on uClibc:
https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/config.gcc;h=82cc9a9959b5ab57c0b8779e054b80cdb95f169b;hb=gcc-6-branch#l1485
https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=e6cdd6b1755033e8f416efaa4334d1294c0a43c6

The Vulkan driver makes use of static_assert
https://cgit.freedesktop.org/mesa/mesa/tree/src/intel/vulkan/anv_private.h?h=12.0#n153

Compiling the Vulkan driver with uClibc and musl fails, therefore this
driver is glibc-only.

Although the configure script does not check for dri3 support if the
Intel Vulkan driver is enabled it needs it nonetheless:
https://cgit.freedesktop.org/mesa/mesa/tree/src/intel/vulkan/anv_wsi_x11.c?h=12.0#n682



Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>