meson: remove meson-created megadrivers symlinks

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=110356


Fixes: aa7afe32 "meson: strip rpath from megadrivers"
Signed-off-by: Eric Engestrom <eric.engestrom@intel.com>
Tested-by: Mike Lothian <mike@fireburn.co.uk>
Reviewed-by: Eric Anholt <eric@anholt.net>
(cherry picked from commit c77acc3c)