ARM: imx_v6_v7_defconfig: enable more USB functions

ARM: imx_v6_v7_defconfig: enable more USB functions

USB Ethernet function at host mode
USB Media function(webcam) at host mode
USB Audio function at host mode
USB Serial function at host mode
USB EHSET driver at host mode (for OTG & EH Certification test)
Several USB Gadget functions:
	- Configfs
	- NCM
	- Zero (used for test)
	- Gadgetfs
	- Serial

Above functions are built as module.

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>