arm64: defconfig: enable crypto userspace API

Enable CONFIG_CRYPTO_USER so that libkcapi can be used. This was tested
using kcapi-rng on a Qualcomm SA8540p automotive development board.

Signed-off-by: Brian Masney <bmasney@redhat.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20221214174607.2948497-1-bmasney@redhat.com