freescale/layerscape: Rename the config CONFIG_SECURE_BOOT name

Rename CONFIG_SECURE_BOOT to CONFIG_NXP_ESBC to avoid conflict
with UEFI secure boot.

Signed-off-by: Udit Agarwal <udit.agarwal@nxp.com>
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/configs/ls1021aqds_nor_SECURE_BOOT_defconfig b/configs/ls1021aqds_nor_SECURE_BOOT_defconfig
index 43b3f6d..8dcd414 100644
--- a/configs/ls1021aqds_nor_SECURE_BOOT_defconfig
+++ b/configs/ls1021aqds_nor_SECURE_BOOT_defconfig
@@ -1,7 +1,7 @@
 CONFIG_ARM=y
 CONFIG_TARGET_LS1021AQDS=y
 CONFIG_SYS_TEXT_BASE=0x60100000
-CONFIG_SECURE_BOOT=y
+CONFIG_NXP_ESBC=y
 CONFIG_NR_DRAM_BANKS=1
 CONFIG_AHCI=y
 # CONFIG_SYS_MALLOC_F is not set