linux-ltd: enable CONFIG_SERIAL_DEV_CTRL_TTYPORT
linux-ltd: enable CONFIG_SERIAL_DEV_CTRL_TTYPORT

Now used by HiKey for wl1835-st support.

Signed-off-by: Ricardo Salveti <6fd42f733b6586c555e01d4ff3116fc7e73e7330@linaro.org>

linaro-technologies/meta-ltd