Convert CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/MIP405_defconfig b/configs/MIP405_defconfig
index 3f8c33a..943ca79 100644
--- a/configs/MIP405_defconfig
+++ b/configs/MIP405_defconfig
@@ -6,6 +6,7 @@
 CONFIG_BOOTDELAY=5
 # CONFIG_CONSOLE_MUX is not set
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
+CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE=y
 # CONFIG_DISPLAY_BOARDINFO is not set
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_I2C=y