Merge patch series "zfs: Fix zfs support on aarch64"

mwleeds@mailtundra.com <mwleeds@mailtundra.com> says:

This patch series is needed to get U-Boot to boot from a ZFS filesystem
on an aarch64 computer. Some of the patches are not architecture specific
and would be needed to boot ZFS on other platforms as well. The ZFS
support in U-Boot hasn't been substantively touched in several years and
to me it seems like it must have been broken for a long time on all
platforms, but I have only tested on aarch64.

Since there doesn't seem to be a mantainer for this area who I can cc,
I'm hoping these patches get seen and pulled in by a general U-Boot
maintainer.

[trini: Per Igor's comment and Phaedrus agreement, dropped his Tested-by
 on the patches themselves]