arm64: defconfig: enable several common USB network adapters

The arm64 system is likely to be used as a host computer instead of
embedded devices and adding USB-Ethernet dongles to make it behave as
host PC is mandatory.

Changelog:
v2: Changed drivers to be as modules instead of built-in.
Signed-off-by: NAkira Tsukamoto <akira.tsukamoto@linaro.org>
Signed-off-by: NGuodong Xu <guodong.xu@linaro.org>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Signed-off-by: NWei Xu <xuwei5@hisilicon.com>

arch/arm64/configs/defconfig

@@ -118,6 +118,16 @@ CONFIG_RAVB=y
 CONFIG_SMC91X=y
 CONFIG_SMSC911X=y
 CONFIG_MICREL_PHY=y
+CONFIG_USB_PEGASUS=m
+CONFIG_USB_RTL8150=m
+CONFIG_USB_RTL8152=m
+CONFIG_USB_USBNET=m
+CONFIG_USB_NET_DM9601=m
+CONFIG_USB_NET_SR9800=m
+CONFIG_USB_NET_SMSC75XX=m
+CONFIG_USB_NET_SMSC95XX=m
+CONFIG_USB_NET_PLUSB=m
+CONFIG_USB_NET_MCS7830=m
 # CONFIG_WLAN is not set
 CONFIG_INPUT_EVDEV=y
 CONFIG_KEYBOARD_GPIO=y