Merge remote-tracking branch 'remotes/alistair/tags/pull-register-20200927' into staging

Two small patches. One with a fix for the register API instance_size
and one for removing unused address variables from load_elf.

# gpg: Signature made Sun 27 Sep 2020 14:45:06 BST
# gpg:                using RSA key F6C4AC46D4934868D3B8CE8F21E10D29DF977054
# gpg: Good signature from "Alistair Francis <alistair@alistair23.me>" [full]
# Primary key fingerprint: F6C4 AC46 D493 4868 D3B8  CE8F 21E1 0D29 DF97 7054

* remotes/alistair/tags/pull-register-20200927:
  core/register: Specify instance_size in the TypeInfo
  load_elf: Remove unused address variables from callers

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>