radv: change base aligmment for allocated memory.

radv: change base aligmment for allocated memory.

On some CIK (Hawaii) this needs to be at least 64k, I'm not 100% sure
it doesn't need to be 128k.

This was causing fast clear eliminate to overwrite the previous buffer,
which since my gfx init code, was the indirect buffer.

Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=99692
Tested-by: Kai Wasserbäch <kai@dev.carbon-project.org>
Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Reviewed-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Cc: "13.0 17.0" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>