Merge changes from topic "fwu-on-stm32mp1" into integration
* changes:
feat(stm32mp1): add support for building the FWU feature
feat(stm32mp1): add logic to pass the boot index to the Update Agent
feat(stm32mp1): add support for reading the metadata partition
feat(stm32mp1): add logic to select the images to be booted
feat(stm32mp1): add GUID's for identifying firmware images to be booted
feat(stm32mp1): add GUID values for updatable images
feat(fwu): add platform hook for getting the boot index
feat(fwu): simplify the assert to check for fwu init
feat(fwu): add a function to pass metadata structure to platforms
feat(partition): add a function to identify a partition by GUID
feat(partition): copy the partition GUID into the partition structure
feat(partition): make provision to store partition GUID value
feat(partition): cleanup partition and gpt headers
feat(fwu): add basic definitions for GUID handling
feat(fwu): pass a const metadata structure to platform routines
build(changelog): add a valid scope for partition code