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/cougarcanyon2_defconfig b/configs/cougarcanyon2_defconfig
index a55e4a3..cfd868d 100644
--- a/configs/cougarcanyon2_defconfig
+++ b/configs/cougarcanyon2_defconfig
@@ -2,6 +2,7 @@
 CONFIG_VENDOR_INTEL=y
 CONFIG_DEFAULT_DEVICE_TREE="cougarcanyon2"
 CONFIG_TARGET_COUGARCANYON2=y
+CONFIG_CONSOLE_MUX=y
 CONFIG_HUSH_PARSER=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set