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/gazerbeam_defconfig b/configs/gazerbeam_defconfig
index 4c565a7..c344a6c 100644
--- a/configs/gazerbeam_defconfig
+++ b/configs/gazerbeam_defconfig
@@ -10,6 +10,7 @@
 CONFIG_SYS_CLK_FREQ=33333333
 CONFIG_ENV_ADDR=0xFE080000
 CONFIG_MPC83xx=y
+CONFIG_SYS_INIT_RAM_LOCK=y
 CONFIG_TARGET_GAZERBEAM=y
 CONFIG_SYSTEM_PLL_VCO_DIV_2=y
 CONFIG_SYSTEM_PLL_FACTOR_4_1=y