MAINTAINERS: Change fsl-qoriq, mpc85xx, mpc86xx maintainers

Change maintainers to Prabhakar Kushwaha for fsl-qoriq, mpc85xx
and mpc86xx.

Signed-off-by: York Sun <york.sun@nxp.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
Acked-by: Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
diff --git a/doc/git-mailrc b/doc/git-mailrc
index 5d835d4..c2eee8c 100644
--- a/doc/git-mailrc
+++ b/doc/git-mailrc
@@ -44,7 +44,7 @@
 alias stroese        Stefan Roese <sr@denx.de>
 alias trini          Tom Rini <trini@konsulko.com>
 alias wd             Wolfgang Denk <wd@denx.de>
-alias yorksun        York Sun <york.sun@nxp.com>
+alias prabhu_kush    Prabhakar Kushwaha <prabhakar.kushwaha@nxp.com>
 
 # Architecture aliases
 alias arch           arc, arm, m68k, microblaze, mips, nds32, nios2, powerpc, sandbox, superh, x86
@@ -86,12 +86,12 @@
 alias nios           uboot, Thomas Chou <thomas@wytron.com.tw>, smcnutt
 alias nios2          nios
 
-alias powerpc        uboot, afleming, stroese, wd, yorksun, mariosix
+alias powerpc        uboot, afleming, stroese, wd, prabhu_kush, mariosix
 alias ppc            powerpc
 alias mpc8xx         uboot, wd, Christophe Leroy <christophe.leroy@c-s.fr>
-alias mpc83xx        uboot, yorksun, mariosix
-alias mpc85xx        uboot, afleming, yorksun
-alias mpc86xx        uboot, afleming, yorksun
+alias mpc83xx        uboot, mariosix
+alias mpc85xx        uboot, afleming, prabhu_kush
+alias mpc86xx        uboot, afleming, prabhu_kush
 
 alias sandbox        sjg
 alias sb             sandbox