Remove myself as i.mx31 maintainer

Remove Peter Chubb as i/MX31 maintainer.

I'm leaving my current job and will no longer have access to the
hardware to test or maintain this port.

Signed-off-by: Peter Chubb <peter.chubb@data61.csiro.au>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
diff --git a/MAINTAINERS b/MAINTAINERS
index 69003cd..58f3421 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -688,7 +688,6 @@
 F: include/hw/watchdog/wdt_imx2.h
 
 i.MX31 (kzm)
-M: Peter Chubb <peter.chubb@nicta.com.au>
 M: Peter Maydell <peter.maydell@linaro.org>
 L: qemu-arm@nongnu.org
 S: Odd Fixes