linux-firmware/i915: Step away from symbolic links and clean up repo.

linux-firmware/i915: Step away from symbolic links and clean up repo.

i915 now loads the specific major/minor version of the firmware
instead of loading the symbolic links.

So this patch also removes symbolic links from the firmware
components that never had the firmware loaded directly and
let the symbolic links only for the cases where some versions
of i915 might load the symbolic link while new versions loads
the file directly.

I considered making copies but this would
increase this repository size in ~ 25%.

The symbolic links now on shall never be updated.

Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>