gcc: Create a linker script to ensure correct link against libgcc

gcc: Create a linker script to ensure correct link against libgcc

On aarch64, GCC builds some emulated functions into the code which come
from libgcc. To ensure that we dynamically link as much as possible,
this script is required so that it will only fall back to pull functions
from the static library if there is no other resort.

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>