Split building coreboot toolchains to a separate file

Specify dependencies specifically for building coreboot toolchains in
the file, so they are not conflated with the dependencies required for
building firmware-open.

Remove building the toolchain when building firmware, so that the new
script is the single source for building coreboot toolchains.

Signed-off-by: Tim Crawford <tcrawford@system76.com>

scripts/coreboot-sdk.sh

@@ -0,0 +1,63 @@
+#!/usr/bin/env bash
+# SPDX-License-Identifier: GPL-3.0-only
+
+# Build the coreboot toolchains
+
+# shellcheck disable=SC1091
+
+set -e
+
+. /etc/os-release
+if [ "$ID" = "arch" ] || [[ "$ID_LIKE" =~ "arch" ]]; then
+    sudo pacman -S --noconfirm \
+        bison \
+        bzip2 \
+        ca-certificates \
+        curl \
+        flex \
+        gcc \
+        gcc-ada \
+        make \
+        patch \
+        tar \
+        xz \
+        zlib
+elif [ "$ID" = "fedora" ] || [[ "$ID_LIKE" =~ "fedora" ]]; then
+    sudo dnf install --assumeyes \
+        bison \
+        bzip2 \
+        ca-certificates \
+        curl \
+        flex \
+        gcc \
+        gcc-c++ \
+        gcc-gnat \
+        make \
+        patch \
+        tar \
+        xz \
+        zlib-devel
+elif [ "$ID" = "ubuntu" ] || [[ "$ID_LIKE" =~ "debian" ]]; then
+    sudo apt-get --quiet update
+    sudo apt-get --quiet install --no-install-recommends --assume-yes \
+        bison \
+        bzip2 \
+        ca-certificates \
+        curl \
+        flex \
+        g++ \
+        gcc \
+        gnat \
+        make \
+        patch \
+        tar \
+        xz-utils \
+        zlib1g-dev
+else
+    printf "\e[1;31munsupported host:\e[0m %s\n" "$ID"
+    exit 1
+fi
+
+make -C coreboot CPUS="$(nproc)" crossgcc-i386
+make -C coreboot CPUS="$(nproc)" crossgcc-x64
+make -C coreboot gitconfig