[BOOTSCRIPT][RPI4][RPI5] Add Clea OS booting process
- Add dynamic selection for bootscript partition using the well defined GPT type GUID for the Clea OS partitions.
- Introduced the Clea OS bootscript file set that replaces the Raspberry default bootscript.
- Add support for RPI4 and RP5.
Signed-off-by: Davide Cardillo davide.cardillo@seco.com