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/orangepi_plus_defconfig b/configs/orangepi_plus_defconfig
index 6c99aa2..bf88fef 100644
--- a/configs/orangepi_plus_defconfig
+++ b/configs/orangepi_plus_defconfig
@@ -10,6 +10,7 @@
 CONFIG_DEFAULT_DEVICE_TREE="sun8i-h3-orangepi-plus"
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
 CONFIG_SYS_EXTRA_OPTIONS="SATAPWR=SUNXI_GPG(11),MACPWR=SUNXI_GPD(6)"
+CONFIG_CONSOLE_MUX=y
 CONFIG_SPL=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set