Dockerfile: Update to gcc-14.2.0 and clang-18

Outside of changing versions here the other visible change is that we
tell grub that riscv64 does not have "large model" support. Without this
change the resulting mkimage is non-functional. This is known upstream
already.

Link: https://savannah.gnu.org/bugs/?65909
Signed-off-by: Tom Rini <trini@konsulko.com>
3 files changed