mailmap: add old address mappings for Randy

Add my old email addresses so that git send-email will map them
to my current email address.

Link: https://lkml.kernel.org/r/20240106063051.13623-1-rdunlap@infradead.org


Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>