arch/csky: enable internal toolchain support
Now that we have support for C-SKY in gcc, binutils and glibc, we can
use Buildroot to build a C-SKY toolchain.
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>