Documentation: Update index.md and add 4.18 release notes

Signed-off-by: Martin Roth <gaumless@gmail.com>
Change-Id: I52814ebbae804ea0ff24a7cec0618054029b8b47
Reviewed-on: https://review.coreboot.org/c/coreboot/+/64843
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Singer <felixsinger@posteo.net>

Documentation/releases/coreboot-4.18-relnotes.md

@@ -0,0 +1,56 @@
+Upcoming release - coreboot 4.18
+================================
+
+The 4.18 release is planned for August 2022.
+
+Update this document with changes that should be in the release notes.
+
+* Please use Markdown.
+* See the past few release notes for the general format.
+* The chip and board additions and removals will be updated right
+  before the release, so those do not need to be added.
+
+Significant changes
+-------------------
+
+### Add significant changes here
+
+
+
+
+
+
+
+
+
+
+
+Plans for Code Deprecation
+--------------------------
+
+
+### Intel Icelake
+
+Intel Icelake code will be removed following the 4.19 release, planned
+for November 2022. This consists of the Intel Icelake SOC and Intel
+Icelake RVP mainboard
+
+Intel Icelake is unmaintained. Also, the only user of this platform ever
+was the CRB board. From the looks of it the code never was ready for
+production as only engineering sample CPUIDs are supported. This reduces
+the maintanence overhead for the coreboot project.
+
+
+### LEGACY_SMP_INIT
+
+Legacy SMP init will be removed from the coreboot master branch
+immediately following this release. Anyone looking for the latest
+version of the code should find it on the 4.18 branch.
+
+This also includes the codepath for SMM_ASEG. This code is used to start
+APs and do some feature programming on each AP, but also set up SMM.
+This has largely been superseded by PARALLEL_MP, which should be able to
+cover all use cases of LEGACY_SMP_INIT, with little code changes. The
+reason for deprecation is that having 2 codepaths to do the virtually
+the same increases maintenance burden on the community a lot, while also
+being rather confusing.

Documentation/releases/index.md

@@ -3,7 +3,7 @@
 ## Upcoming release
 
 Please add to the release notes as changes are added:
-* [4.17 - May 2022](coreboot-4.17-relnotes.md)
+* [4.18 - Aug 2022](coreboot-4.18-relnotes.md)
 
 The [checklist] contains instructions to ensure that a release covers all
 important things and provides a reliable format for tarballs, branch
@@ -15,6 +15,7 @@ important is taken care of.
 
 ## Previous releases
 
+* [4.17 - May 2022](coreboot-4.17-relnotes.md)
 * [4.16 - Feb 2022](coreboot-4.16-relnotes.md)
 * [4.15 - November 2021](coreboot-4.15-relnotes.md)
 * [4.14 - May 2021](coreboot-4.14-relnotes.md)