Convert CONFIG_SYS_CONSOLE_IS_IN_ENV to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_CONSOLE_IS_IN_ENV

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/ci20_mmc_defconfig b/configs/ci20_mmc_defconfig
index aa2d087..3c45520 100644
--- a/configs/ci20_mmc_defconfig
+++ b/configs/ci20_mmc_defconfig
@@ -19,6 +19,7 @@
 CONFIG_BOOTARGS="console=ttyS4,115200 rw rootwait root=/dev/mmcblk0p1"
 CONFIG_USE_BOOTCOMMAND=y
 CONFIG_BOOTCOMMAND="ext4load mmc 0:1 0x88000000 /boot/uImage; bootm 0x88000000"
+CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_DISPLAY_CPUINFO=y
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_MISC_INIT_R=y