ARM: imx_v6_v7_defconfig: Select ULPI support

Select CONFIG_USB_CHIPIDEA_ULPI and CONFIG_USB_ULPI_BUS so that
USB ULPI can be functional on some boards like imx51-babbge.

This fixes a kernel hang in 4.18-rc1 on i.mx51-babbage, caused by commit
03e6275a ("usb: chipidea: Fix ULPI on imx51").

Suggested-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>