Updates for 2.2.0-rc2 release

Update release notes and the various release version files.

Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/README.md b/README.md
index e554ba4..081d884 100644
--- a/README.md
+++ b/README.md
@@ -18,7 +18,7 @@
 [travis]: https://travis-ci.org/mcu-tools/mcuboot
 [license]: https://github.com/mcu-tools/mcuboot/blob/main/LICENSE
 
-This is MCUboot version 2.2.0-rc1
+This is MCUboot version 2.2.0-rc2
 
 MCUboot is a secure bootloader for 32-bits microcontrollers. It defines a
 common infrastructure for the bootloader and the system flash layout on
diff --git a/docs/index.md b/docs/index.md
index 1565434..a4744f3 100644
--- a/docs/index.md
+++ b/docs/index.md
@@ -1,7 +1,7 @@
 # MCUboot
 
 MCUboot is a secure bootloader for 32-bits microcontrollers.  This document is
-for release v2.2.0-rc1.
+for release v2.2.0-rc2.
 
 Please see [Contributing](contributing.md) on how you can contribute to MCUboot.
 
diff --git a/docs/release-notes.md b/docs/release-notes.md
index 1eebd41..2eb7537 100644
--- a/docs/release-notes.md
+++ b/docs/release-notes.md
@@ -76,6 +76,16 @@
 - Fixed issue with watchdog not being fed during flash erase
   operations, which could cause the watchdog to time out on long
   erase operations and prevent firmware updates from being possible.
+- Fix issues related to calculating the maximum image size for a given
+  configuration.
+- Fix an issue with sha hash calculations in a loop.
+- Fix an issue with the security counter being updated before an image is
+  confirmed.
+- Added a contributing guideline.
+- Fixed an issue related to referencing the arm-vector table of the
+  application, which caused a jump to the incorrect address instead of the
+  application reset vector for some Zephyr builds when LTO (link time
+  optimization) was enabled.
 
 ## Version 2.1.0
 
diff --git a/scripts/imgtool/__init__.py b/scripts/imgtool/__init__.py
index c822b84..24aec1b 100644
--- a/scripts/imgtool/__init__.py
+++ b/scripts/imgtool/__init__.py
@@ -14,4 +14,4 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-imgtool_version = "2.2.0rc1"
+imgtool_version = "2.2.0rc2"