This upgrades the recipe to 17.2.6 bugfix release.
The changes can be seen at:
https://www.mesa3d.org/relnotes/17.2.6.html
(From OE-Core rev: 7e924e1607d8aad0f8d48f0be01931c468df2019)
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>