Various fixes + cleanup.

- Add parts.rst documentation for Linux kernel.
- Completely fix problems caused by new bootstrap, update checksums for
  /usr.
- Globalise populate_device_nodes.
- Enable deblobbing.

sysa/pkg-config-0.29.2/pkg-config-0.29.2.sh

@@ -1,16 +0,0 @@
-# SPDX-FileCopyrightText: 2021 Andrius Štikonas <andrius@stikonas.eu>
-#
-# SPDX-License-Identifier: GPL-3.0-or-later
-
-src_prepare() {
-    autoreconf -fi
-}
-
-src_configure() {
-    # We use internal glib because standalone glib library depends on
-    # pkg-config and other software (python/meson) that we do not have.
-    ./configure \
-        --prefix="${PREFIX}" \
-        --build=i386-unknown-linux-musl \
-        --with-internal-glib
-}