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/h8_homlet_v2_defconfig b/configs/h8_homlet_v2_defconfig
index c4bd2c5..76dd833 100644
--- a/configs/h8_homlet_v2_defconfig
+++ b/configs/h8_homlet_v2_defconfig
@@ -9,6 +9,7 @@
 CONFIG_AXP_GPIO=y
 CONFIG_DEFAULT_DEVICE_TREE="sun8i-a83t-allwinner-h8homlet-v2"
 # CONFIG_SYS_MALLOC_CLEAR_ON_INIT is not set
+CONFIG_CONSOLE_MUX=y
 CONFIG_SPL=y
 # CONFIG_CMD_IMLS is not set
 # CONFIG_CMD_FLASH is not set