arm64: defconfig: build-in Qualcomm SC7180 and SM8450 interconnects

On Qualcomm SC7180 and SM8450 SocS, the typical debug console serial
port is part of GENI Serial Engine QUP Wrapper Controller which uses
interconnects.  This means that without interconnect drivers, the serial
might not probe.  Without serial console, the root might not be mounted
by initramfs:

  + REASON=No init found. Try passing init= bootarg. PS1=(initramfs
  ...
  (initramfs) run-init -c /dev/console -n /root /sbin/init
  run-init: opening console: No such file or directory

This means that interconnect drivers on these Qualcomm SoCs cannot be
modules and must be built-in to mount rootfs.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>