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/ls1021aqds_sdcard_ifc_defconfig b/configs/ls1021aqds_sdcard_ifc_defconfig
index ec9c247..8c8355a 100644
--- a/configs/ls1021aqds_sdcard_ifc_defconfig
+++ b/configs/ls1021aqds_sdcard_ifc_defconfig
@@ -2,6 +2,7 @@
 CONFIG_TARGET_LS1021AQDS=y
 CONFIG_SPL_LIBCOMMON_SUPPORT=y
 CONFIG_SPL_LIBGENERIC_SUPPORT=y
+CONFIG_SYS_FSL_DDR3=y
 CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_SPL_MMC_SUPPORT=y
 CONFIG_SPL_SERIAL_SUPPORT=y
@@ -13,10 +14,11 @@
 CONFIG_FIT=y
 CONFIG_FIT_VERBOSE=y
 CONFIG_SYS_EXTRA_OPTIONS="RAMBOOT_PBL,SPL_FSL_PBL,SD_BOOT"
-CONFIG_SYS_FSL_DDR3=y
 CONFIG_SD_BOOT=y
 CONFIG_BOOTDELAY=3
 CONFIG_SILENT_CONSOLE=y
+# CONFIG_CONSOLE_MUX is not set
+CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_SPL=y
 CONFIG_SPL_MPC8XXX_INIT_DDR_SUPPORT=y
 CONFIG_HUSH_PARSER=y