arm64: defconfig: Demote Qualcomm USB PHYs to modules

The Qualcomm USB PHYs are not critical for reaching the ramdisk to load
modules, so they can be demoted to be built as such instead of builtin.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Vinod Koul <vkoul@kernel.org>
Link: https://lore.kernel.org/r/20220712031821.4134712-1-bjorn.andersson@linaro.org