redhat/configs: enable CONFIG_CMA on aarch64 as tech-preview

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2043141

Upstream Status: RHEL only

Tested: Booted kernel with and without "cma=64M" and verified that the kernel only gets tainted in the latter case.

This is essentially the kernel-ark change [1], exclusing fedora specific things no longer part of cs9. I tried to keep the CONFIG structure as close as possible to the kernel-ark structure.

Enable CONFIG_CMA on aarch64 just as we have it already for x86-64.

While in tech-preview, we'll require a manual configuration of cma on the kernel command line -- we will default to "cma=0". Once e.g., "cma=64M" has been specified, cma_activate_area() will call mark_tech_preview("CMA"), essentially tainting the kernel. Once no longer in tech-preview, we can enable CMA as default by e.g., similarly defaulting to "cma=64M".

The real change is preceded by some cleanups around CMA configs.

[1] cki-project/kernel-ark!1592 (merged)

Signed-off-by: David Hildenbrand david@redhat.com