Updates for 2.2.0-rc2 release

[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

# 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.

- 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

# See the License for the specific language governing permissions and

# limitations under the License.

imgtool_version = "2.2.0rc1"

imgtool_version = "2.2.0rc2"