Recently OpenRISC added support for external initrd images, but I found
some instability when using larger buildroot initrd images. It turned
out that I forgot to reserve the memblock space for the initrd image.
This patch fixes the instability issue by reserving memblock space.
Fixes: ff6c923dbec3 ("openrisc: Add support for external initrd images")
Signed-off-by: Stafford Horne <shorne@gmail.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>