ARM: imx_v6_v7_defconfig: Remove unneeded options

Remove the following unneeded config options:

- CONFIG_USB_CHIPIDEA_ULPI and CONFIG_USB_ULPI_BUS have been removed
since commit a930d8bd ("usb: chipidea: Always build ULPI code")

- CONFIG_DEBUG_FS is selected by default.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>