arm64: defconfig: Enable QCOM_IOMMU

Enable QCOM IOMMU driver for 'B' family devices, such as APQ8016 found on the
Dragonboard 410c. With this change, graphics console and GPU are working
fine (using mesa/freedreno for GPU driver).
Signed-off-by: Nicolas Dechesne <nicolas.dechesne@linaro.org>
Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm64/configs/defconfig

@@ -516,6 +516,7 @@ CONFIG_HI6220_MBOX=y
 CONFIG_ROCKCHIP_IOMMU=y
 CONFIG_ARM_SMMU=y
 CONFIG_ARM_SMMU_V3=y
+CONFIG_QCOM_IOMMU=y
 CONFIG_RPMSG_QCOM_SMD=y
 CONFIG_RASPBERRYPI_POWER=y
 CONFIG_QCOM_SMEM=y