A certain amount of dynamic space is required for the handover from
GRUB/Linux-EFI-stub. This entails things like initrd addresses,
address-cells entries and associated strings.
But move this into a proper centralised #define rather than live-code
it in the loader.
Signed-off-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>