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/s5p_goni_defconfig b/configs/s5p_goni_defconfig
index cacc443..4cbf022 100644
--- a/configs/s5p_goni_defconfig
+++ b/configs/s5p_goni_defconfig
@@ -2,6 +2,7 @@
 CONFIG_ARCH_S5PC1XX=y
 CONFIG_TARGET_S5P_GONI=y
 CONFIG_DEFAULT_DEVICE_TREE="s5pc1xx-goni"
+CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="Goni # "
 # CONFIG_AUTOBOOT is not set