build: allow specifying custom ramdisk
requested to merge amartinz/halium-generic-adaptation-build-tools:halium-10-focal-ramdisk into halium-10-focal
To use a prebuilt file:
deviceinfo_prebuilt_ramdisk="prebuilts/ramdisk.img"
To download a prebuilt ramdisk:
deviceinfo_prebuilt_ramdisk_source="https://github.com/halium/initramfs-tools-halium/releases/download/continuous/initrd.img-touch-arm64"
Edited by Alexander Martinz