toolchain/gcc: remove upstreamed patch, add backport

toolchain/gcc: remove upstreamed patch, add backport

This patch has been upstream since GCC 10.
Dragan Mladjenovic (2):
      Emit .note.GNU-stack for soft-float linux targets.
      Emit .note.GNU-stack for hard-float linux targets.

Link: https://gcc.gnu.org/g:a3c1e1f2ff88
Link: https://gcc.gnu.org/g:54b3d52c3cca
Add backport patch to define TARGET_LIBC_GNUSTACK on musl to add
.note.GNU-stack on hard-float MIPS targets.

Link: https://gcc.gnu.org/g:25abbb924968
The net effect should be the exact same functionality while following
upstream code instead of a custom outdated patch.

Signed-off-by: Ilya Lipnitskiy <ilya.lipnitskiy@gmail.com>