arm64: defconfig: enable several common USB network adapters

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: Akira Tsukamoto <akira.tsukamoto@linaro.org>
Signed-off-by: Guodong Xu <guodong.xu@linaro.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Wei Xu <xuwei5@hisilicon.com>