mailmap: Update mail address for Igor Opaniuk

My address at Linaro doesn't exist anymore, so people
keep getting mail delivery error responses. Map this address
to the actual one.

Signed-off-by: Igor Opaniuk <igor.opaniuk@gmail.com>
Reviewed-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>

.mailmap

@@ -29,6 +29,7 @@ Jagan Teki <jaganna@gmail.com>
 Jagan Teki <jaganna@xilinx.com>
 Jagan Teki <jagannadh.teki@gmail.com>
 Jagan Teki <jagannadha.sutradharudu-teki@xilinx.com>
+Igor Opaniuk <igor.opaniuk@gmail.com> <igor.opaniuk@linaro.org>
 Markus Klotzbuecher <mk@denx.de>
 Paul Burton <paul.burton@mips.com> <paul.burton@imgtec.com>
 Prabhakar Kushwaha <prabhakar@freescale.com>