arm64: defconfig: Enable Qualcomm QUSB2 PHY

Tested on the Lenovo Yoga C630 where this patch enables USB.
Without it USB devices are not enumerated.

Link: https://lore.kernel.org/r/20190903192625.14775-3-lee.jones@linaro.org


Signed-off-by: Lee Jones <lee.jones@linaro.org>
Reviewed-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>