DEVELOPERS: rename the stm32f4?9_disco_defconfig entries

Commit 494807e28dd4 (configs/stm32f4{2|6}9_*_defconfig: rename
configurations) forgot to also rename the corresponding entries
in the DEVELOPERS file.

Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
Cc: Dario Binacchi <dariobin@libero.it>
Cc: Christophe Priouzeau <christophe.priouzeau@foss.st.com>

DEVELOPERS

@@ -529,8 +529,8 @@ F:	package/tini/
 N:	Christophe Priouzeau <christophe.priouzeau@foss.st.com>
 F:	board/stmicroelectronics/stm32f429-disco/
 F:	board/stmicroelectronics/stm32f469-disco/
-F:	configs/stm32f429_disco_defconfig
-F:	configs/stm32f469_disco_defconfig
+F:	configs/stm32f429_disco_xip_defconfig
+F:	configs/stm32f469_disco_sd_defconfig
 
 N:	Christophe Vu-Brugier <cvubrugier@fastmail.fm>
 F:	package/drbd-utils/