efi_loader: Swap roles with Heinrich

Heinrich is going to take over maintainership of the efi_loader tree
going forward.

To ensure that I will still receive review mails at least, add me as
reviewer with a stable email address.

Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Tom Rini <trini@konsulko.com>