arm: toradex: Convert CONFIG_CONSOLE_MUX to Kconfig

This converts the following to Kconfig:
   CONFIG_CONSOLE_MUX

Cc: Igor Opaniuk <igor.opaniuk@toradex.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Igor Opaniuk <igor.opaniuk@toradex.com>
diff --git a/configs/apalis_imx6_defconfig b/configs/apalis_imx6_defconfig
index 65162a2..bad8a60 100644
--- a/configs/apalis_imx6_defconfig
+++ b/configs/apalis_imx6_defconfig
@@ -19,8 +19,6 @@
 CONFIG_FIT=y
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/mach-imx/spl_sd.cfg,MX6Q"
 CONFIG_BOOTDELAY=1
-# CONFIG_CONSOLE_MUX is not set
-CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_MISC_INIT_R=y
 CONFIG_VERSION_VARIABLE=y
 # CONFIG_DISPLAY_BOARDINFO is not set
diff --git a/configs/colibri_imx6_defconfig b/configs/colibri_imx6_defconfig
index ca33327..e5f8a73 100644
--- a/configs/colibri_imx6_defconfig
+++ b/configs/colibri_imx6_defconfig
@@ -18,8 +18,6 @@
 CONFIG_FIT=y
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=arch/arm/mach-imx/spl_sd.cfg,MX6DL"
 CONFIG_BOOTDELAY=1
-# CONFIG_CONSOLE_MUX is not set
-CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_MISC_INIT_R=y
 CONFIG_VERSION_VARIABLE=y
 # CONFIG_DISPLAY_BOARDINFO is not set
diff --git a/include/configs/apalis_imx6.h b/include/configs/apalis_imx6.h
index 38d0a6e..8026211 100644
--- a/include/configs/apalis_imx6.h
+++ b/include/configs/apalis_imx6.h
@@ -74,7 +74,6 @@
 #define CONFIG_BMP_16BPP
 #define CONFIG_VIDEO_LOGO
 #define CONFIG_VIDEO_BMP_LOGO
-#define CONFIG_CONSOLE_MUX
 #define CONFIG_IMX_HDMI
 #define CONFIG_IMX_VIDEO_SKIP
 
diff --git a/include/configs/colibri_imx6.h b/include/configs/colibri_imx6.h
index f5f86f0..3d3f313 100644
--- a/include/configs/colibri_imx6.h
+++ b/include/configs/colibri_imx6.h
@@ -62,7 +62,6 @@
 #define CONFIG_BMP_16BPP
 #define CONFIG_VIDEO_LOGO
 #define CONFIG_VIDEO_BMP_LOGO
-#define CONFIG_CONSOLE_MUX
 #define CONFIG_IMX_HDMI
 #define CONFIG_IMX_VIDEO_SKIP