Update the linux kernel for sysb/c to 4.9.10.

- We do not use latest 4.9.x because it relies on a new version of
  binutils, while older versions do not. (Note: we should be able to go
  a bit newer but I didn't bother testing >50 versions to figure this
  out).
- We do not use newer kernel versions because they require one or more
  of (new perl, new binutils, new make, new gcc, new bison, new tar).
- sysb and sysc are updated to use the SATA (libata) subsystem (aka sda)
  instead of IDE-emulating SATA subsystem (aka hda) which is now
  available to us.
- While theoretically according to docs 4.9 should work OOTB with our
  version of binutils this is not the case, so we have to do a bit of
  (interesting) patching. But this does not break anything.
- Thankfully serial support in 4.9 is not screwed over like it is in 2.6
  so we can revert to that.
- 4.9 has the linux-libre project at our disposal, instead of gNewSense.
  So we use this. Unfortunatley that takes forever because we have to
  use sed because our version of gawk is too old/buggy. :( I plan to
  introduce very shortly 1. parallelism 2. 'sysc snapshot' which will
  start from sysc to avoid this. I do not want to use linux-libre
  tarballs because they make modificiations directly from this script
  (aka not easily verifiable, use the source!) and this script allows
  for much greater flexibility.
- We compile the initramfs ahead-of-build using the in-tree cpio
  generator instead of also building cpio to use less packages. We do
  NOT build the initramfs into the kernel like 2.6 (unsupported).
- Oh and fix a kexec-tools checksum.

sysa/linux-4.9.10/patches/use-less-ram.patch

@@ -0,0 +1,22 @@
+SPDX-FileCopyrightText: 2021 fosslinux <fosslinux@aussies.space>
+
+SPDX-License-Identifier: GPL-2.0-only
+
+For some reason (old version of sed/bash?), this falsepos sed thing uses a
+lot of RAM within bash and causes an overflow which is caught by bash
+but prompts it to crash. As we are not using falsepos detection anyway it
+is unused and hence can be set to an empty value.
+
+--- deblob-check	2021-07-30 09:28:09.324276561 +1000
++++ deblob-check	2021-07-30 09:28:31.742449255 +1000
+@@ -7232,9 +7232,7 @@
+ # $4 is the action for every complete input pattern.
+ 
+ set_sed_main () {
+-  falsepos=`${SED-sed} -n 's,^[+]\^*,,p' < "$regex_name" |
+-    ${SED-sed} -n -e 's,[$]$,\\\\([\\\\n]\\\\|$\\\\),' \
+-	-e '1h; 1!H; ${g;s,[\n],\\\\|,g;s,^\(..*\)$,\\\\(\1\\\\),;p;}'`
++  falsepos=
+   blobs=`${SED-sed} -n 's,^[-],,p' < "$regex_name" |
+     ${SED-sed} -n -e 's,[$]$,\\\\([\\\\n]\\\\|$\\\\),' \
+ 	-e '1h; 1!H; ${g;s,[\n],\\\\|,g;s,^\(..*\)$,\\\\(\1\\\\),;p;}'`