arm: mvebu: Remove SYS_MALLOC_CLEAR_ON_INIT from DB-MV784MP-GP AXP board

By removing CONFIG_SYS_MALLOC_CLEAR_ON_INIT, the bootup time is a bit
faster.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Luka Perkov <luka.perkov@sartura.hr>
diff --git a/configs/db-mv784mp-gp_defconfig b/configs/db-mv784mp-gp_defconfig
index d8c667a..6dda2ae 100644
--- a/configs/db-mv784mp-gp_defconfig
+++ b/configs/db-mv784mp-gp_defconfig
@@ -3,6 +3,7 @@
 CONFIG_SYS_MALLOC_F_LEN=0x2000
 CONFIG_TARGET_DB_MV784MP_GP=y
 CONFIG_DEFAULT_DEVICE_TREE="armada-xp-gp"
+# CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 CONFIG_SPL=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set