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/igep0032_defconfig b/configs/igep0032_defconfig
index b2c5c71..4fbbf63 100644
--- a/configs/igep0032_defconfig
+++ b/configs/igep0032_defconfig
@@ -3,6 +3,7 @@
 # CONFIG_SPL_EXT_SUPPORT is not set
 CONFIG_TARGET_OMAP3_IGEP00X0=y
 CONFIG_SYS_EXTRA_OPTIONS="MACH_TYPE=MACH_TYPE_IGEP0032,BOOT_ONENAND"
+CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_VERSION_VARIABLE=y
 CONFIG_SPL=y
 CONFIG_SPL_MTD_SUPPORT=y