arm: ls102xa: Enable CONFIG_SYS_CONSOLE_IS_IN_ENV support

CONFIG_SYS_CONSOLE_IS_IN_ENV needs to be enabled, so we could set stdout
environment variable to specify the vga for the console output when
LCD/HDMI is connected to the boards.

Signed-off-by: Alison Wang <alison.wang@nxp.com>
Reviewed-by: York Sun <york.sun@nxp.com>
2 files changed