Update libmfx-gen to version 21.3.4 / rev 4 via SR 924811
https://build.opensuse.org/request/show/924811
by user sndirsch + dimstar_suse
- U_Removed-proprietary-mentions-from-file-headers-1023.patch
* upstream patch, which replaces proprietary Intel license with
OpenSource MIT license (github issue#183)
- this addresses the legal issues we had with checkin for sle15-sp4/
Leap 15.4