pkg/debian: Disable Intel IOMMU by default

IOMMU breaks ME and thus IPTS on gen5/6 devices. So disable it by
default.

pkg/debian/kernel/ubuntu.config

@@ -56,3 +56,9 @@ CONFIG_ACPI_I2C_OPREGION=y
 ##
 
 # CONFIG_INPUT_EVBUG is not set
+
+##
+## Do not enable Intel IOMMU by default, it breaks IPTS/ME.
+##
+
+CONFIG_INTEL_IOMMU_DEFAULT_ON=n