usb: chipidea: Always build ULPI code

Commit 03e6275a ("usb: chipidea: Fix ULPI on imx51") causes a kernel
hang on imx51 systems that use the ULPI interface and do not select the
CONFIG_USB_CHIPIDEA_ULPI option.

In order to avoid such potential misuse, let's always build the
chipidea ULPI code into the final ci_hdrc object.

Tested on a imx51-babbage board.

Fixes: 03e6275a

 ("usb: chipidea: Fix ULPI on imx51")
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>