Convert CONFIG_SYS_INIT_RAM_LOCK to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_INIT_RAM_LOCK

Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/T2080QDS_SECURE_BOOT_defconfig b/configs/T2080QDS_SECURE_BOOT_defconfig
index 9b3ffe5..418b994 100644
--- a/configs/T2080QDS_SECURE_BOOT_defconfig
+++ b/configs/T2080QDS_SECURE_BOOT_defconfig
@@ -3,6 +3,7 @@
 CONFIG_ENV_SIZE=0x2000
 CONFIG_DEFAULT_DEVICE_TREE="t2080qds"
 CONFIG_MPC85xx=y
+CONFIG_SYS_INIT_RAM_LOCK=y
 CONFIG_TARGET_T2080QDS=y
 CONFIG_MPC85XX_HAVE_RESET_VECTOR=y
 CONFIG_ENABLE_36BIT_PHYS=y