Infineon: Add cyw20829 platform, shared slot feature, json memory map, psoc6 xip

Based in 1.8.0 release of MCUBoot library

This commit adds CYW20829 Infineon platform support with following capabilities:
1. Overwrite and swap upgrade mode support
2. Multi-image with up to 4 images
3. Hardware security counter is supported for CYW20829 platform

Add XIP support for PSOC6 platform - place BOOT slot in external memory and execute it in place using SMIF in XIP mode

and some new features for Infineon devices.

1. Shared upgrade slot feature - use one shared area for upgrade slots of multiple images
2. Memory map defined using JSON file - define memory regions for bootloader and user app in conventional way using JSON file
diff --git a/docs/release.md b/docs/release.md
index ff00cec..90c32b5 100644
--- a/docs/release.md
+++ b/docs/release.md
@@ -32,7 +32,7 @@
 time, and allow testing to happen.
 
 During the time between rc1 and the final release, the only changes
-that should be merged into master are those to fix bugs found in the
+that should be merged into main are those to fix bugs found in the
 rc and Mynewt metadata as described in the next section.
 
 ## imgtool release
@@ -81,7 +81,7 @@
 At this point, the tag can be pushed to github to make the actual
 release happen:
 ``` bash
-git push origin HEAD:refs/heads/master
+git push origin HEAD:refs/heads/main
 git push origin va.b.c-rcn
 ```