temp/xf86-video-opentegra fails to build for armv7

From https://builds.sr.ht/~postmarketos/job/894457#task-pmbootstrap_build:

./exa/gen_shaders_h.sh ./exa
make[2]: ./exa/gen_shaders_h.sh: No such file or directory
make[2]: *** [Makefile:1237: exa/shaders.h] Error 127
make[2]: Leaving directory '/home/pmos/build/src/xf86-video-opentegra-9be4b4aa7c81b9b43496e8621954a0f4b343f3b1/src'
make[1]: *** [Makefile:520: all-recursive] Error 1
make[1]: Leaving directory '/home/pmos/build/src/xf86-video-opentegra-9be4b4aa7c81b9b43496e8621954a0f4b343f3b1'
make: *** [Makefile:431: all] Error 2
>>> ERROR: xf86-video-opentegra: build failed

I've removed it for v22.12 since only devices in testing use it.

@okias: you are listed as maintainer, can you take a look?

CC people who modified it: @Maxnet, @jenneron

I also wonder whether it makes sense to move this to alpine.