serial-uartlite: Change logic how console_port is setup

Change logic how console_port is setup by using CON_ENABLED flag
instead of index. There will be unique uart_console
structure that's why code can't use id for console_port
assignment.

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Link: https://lore.kernel.org/r/1573555271-2579-1-git-send-email-shubhrajyoti.datta@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>