Convert CONFIG_SYS_DEVICE_NULLDEV to Kconfig
This converts the following to Kconfig:
CONFIG_SYS_DEVICE_NULLDEV
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/README.silent b/doc/README.silent
index 6d90a0e..00288e0 100644
--- a/doc/README.silent
+++ b/doc/README.silent
@@ -19,7 +19,7 @@
- When the console devices have been initialized, "stdout" and
"stderr" are set to "nulldev", so subsequent messages are
suppressed automatically. Make sure to enable "nulldev" by
- #defining CONFIG_SYS_DEVICE_NULLDEV in your board config file.
+ enabling CONFIG_SYS_DEVICE_NULLDEV in your board defconfig file.
- When booting a linux kernel, the "bootargs" are fixed up so that
the argument "console=" will be in the command line, no matter how