So far it was only possible to specify the size of the ramdisk
via the kernel commandline option: ramdisk_size. In a remote
deployment it was therefore required to carry this size as a
mandatory information to the deployment server. With this commit
we allow to specify the size for the ramdisk to be configured as
part of the image configuration which makes this information
also available inside of the initrd. If provided the ramdisk_size
kernel commandline option still takes precedence over the
<oem-ramdisk-size> setting to avoid any behavior change and to
still allow dynamic overrides of the ramdisk size.
313f296587