.mailmap: fix old email addresses

Update Nick & Nadia's old addresses.

Link: https://lkml.kernel.org/r/20210406134036.GQ2531743@casper.infradead.org
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nadia Yvette Chambers <nyc@holomorphy.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

.mailmap

@@ -254,8 +254,14 @@ Morten Welinder <welinder@anemone.rentec.com>
 Morten Welinder <welinder@darter.rentec.com>
 Morten Welinder <welinder@troll.com>
 Mythri P K <mythripk@ti.com>
+Nadia Yvette Chambers <nyc@holomorphy.com> William Lee Irwin III <wli@holomorphy.com>
 Nathan Chancellor <nathan@kernel.org> <natechancellor@gmail.com>
 Nguyen Anh Quynh <aquynh@gmail.com>
+Nicholas Piggin <npiggin@gmail.com> <npiggen@suse.de>
+Nicholas Piggin <npiggin@gmail.com> <npiggin@kernel.dk>
+Nicholas Piggin <npiggin@gmail.com> <npiggin@suse.de>
+Nicholas Piggin <npiggin@gmail.com> <nickpiggin@yahoo.com.au>
+Nicholas Piggin <npiggin@gmail.com> <piggin@cyberone.com.au>
 Nicolas Ferre <nicolas.ferre@microchip.com> <nicolas.ferre@atmel.com>
 Nicolas Pitre <nico@fluxnic.net> <nicolas.pitre@linaro.org>
 Nicolas Pitre <nico@fluxnic.net> <nico@linaro.org>