main/raspberrypi-bootloader: create new -common subpackage, add missing deps
Create a new raspberrypi-bootloader-common package and move bootcode.bin to it.
Other subpackages previously had missing dependancies for the package containing bootcode.bin file. Add dependancies to these subpackages, and to raspberrypi-bootloader, on raspberrypi-bootloader-common to satisfy this file requirement.