ci: Uprev kernel version for Mesa CI

Update Mesa CI Linux Kernel version

Target version: v5.15

https://gitlab.freedesktop.org/gfx-ci/linux/-/tree/v5.15-for-mesa-ci

Kconfig changes

• Update Kconfig for x86_64 and ARM64. Follow the dependency tree of the kernel modules to make sure that the intended configurations are being set. Check scripts/merge_config.sh output as well to see if there is a requested Kconfig not being considered.

For a530 devices:

• Use kernel cmdline maxcpus=2, to disable support for cpufreq scaling

For a630 devices:

• Use kernel version with a6xx workaround for frequency scaling
• Enable CONFIG_QCOM_LMH targeting a630 slowness on new kernel

Out of mainline tree patches used

For x86 jobs:

• Use a fix for virtio.c skb tailroom calculation, which was causing kernel panics on virgl-test jobs. gfx-ci/linux@4bcfb0d0

For a360 device:

• Revert a commit which removes slpi_region from msm8996. gfx-ci/linux@27038b72

Failing jobs

There are some jobs failing, fortunately they are all manual jobs. So probably is not well-maintained as the automatic ones.

• Source pipeline: https://gitlab.freedesktop.org/gallo/mesa/-/pipelines/434295
• Failing jobs: https://gitlab.freedesktop.org/gallo/mesa/-/pipelines/434295/failures

The problems have been solved by updating trace and conformance tests expectations