ACPI/IORT: Remove linker section for IORT entries probing

The IORT linker section introduced by commit 34ceea27
("ACPI/IORT: Introduce linker section for IORT entries probing")
was needed to make sure SMMU drivers are registered (and therefore
probed) in the kernel before devices using the SMMU have a chance
to probe in turn.

Through the introduction of deferred IOMMU configuration the linker
section based IORT probing infrastructure is not needed any longer, in
that device/SMMU probe dependencies are managed through the probe
deferral mechanism, making the IORT linker section infrastructure
unused, so that it can be removed.

Remove the unused IORT linker section probing infrastructure
from the kernel to complete the ACPI IORT IOMMU configure probe
deferral mechanism implementation.

Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>