Convert CONFIG_SYS_CONSOLE_IS_IN_ENV and CONFIG_CONSOLE_MUX to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_CONSOLE_IS_IN_ENV
   CONFIG_CONSOLE_MUX

Signed-off-by: Simon Glass <sjg@chromium.org>
[trini: Re-order, re-migrate]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/ge_b450v3_defconfig b/configs/ge_b450v3_defconfig
index 8577167..29010f3 100644
--- a/configs/ge_b450v3_defconfig
+++ b/configs/ge_b450v3_defconfig
@@ -3,6 +3,7 @@
 CONFIG_TARGET_GE_B450V3=y
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 CONFIG_BOOTDELAY=1
+CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_HUSH_PARSER=y
 CONFIG_CMD_BOOTZ=y
 # CONFIG_CMD_IMLS is not set