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/P1010RDB-PB_36BIT_NAND_defconfig b/configs/P1010RDB-PB_36BIT_NAND_defconfig
index 135cd03..52d2550 100644
--- a/configs/P1010RDB-PB_36BIT_NAND_defconfig
+++ b/configs/P1010RDB-PB_36BIT_NAND_defconfig
@@ -14,6 +14,7 @@
 CONFIG_SPL=y
 CONFIG_TPL_MAX_SIZE=0x20000
 CONFIG_MPC85xx=y
+CONFIG_SYS_INIT_RAM_LOCK=y
 CONFIG_TARGET_P1010RDB_PB=y
 CONFIG_ENABLE_36BIT_PHYS=y
 CONFIG_SYS_MPC85XX_NO_RESETVEC=y