SMMU: basic driver for init and probing

Introducing the driver in kernel for detecting SMMU features
and initialise the hardware.

Signed-off-by: Oliver Scott <Oliver.Scott@data61.csiro.au>

Convert license tags to SPDX identifiers

This commit also converts our own copyright headers to directly use
SPDX, but leaves all other copyright header intact, only adding the
SPDX ident. As far as possible this commit also merges multiple
Data61 copyright statements/headers into one for consistency.

arm/tk1: make SMMU memory static

The tk1 SMMU implementation does not need to dynamically allocate
memory as the PDs are not managed by user-level. Convert to static.

style: consistently attach return type

Add attach-return-type to astyle

style: correct parenthesis padding

Use astyle's unpad-paren to unpad all parentheses that are not included
by pad-header, pad-oper, and pad-comma.

tk1: Remove stray devices.h reference

Share linker.h between architectures

tk1: Add register clobbers to monitor mode call

tk1: Fix config bug that masked IOMMU interrupts

arm: Config option for enabling SMMU interrupts

SMMU interrupts are handled and acknowledged entirely in the kernel. As a result
rapid SMMU faults can cause excessive kernel time, and if printing is enabled
potentially result in a complete Denial of Service.

tk1: Remove temporary SMMU memory mapping support

SELFOUR-556: Rationalize BITS vs INDEX_BITS

s/SMMU_PD_BITS/SMMU_PD_INDEX_BITS
Current convention is to say that X_BITS is the log base 2
size of an object, not the log base 2 number of indices

SELFOUR-552: Translate IO-ASIDs->PDs by table

Previously looking up the page directory base for a SysteMMU was
done by writing the ASID into the hardware and reading out the
currently set page directory for that ASID. This is confusing for
verification so this commit introduces a global translation table
for converting an ASID to a page directory.

arm-hyp: Minor cleanups

Cleanup some small licensing, whitespace and configuration details

arm-hyp/tk1: add guards so other plats can compile.

arm-hyp/tk1: address review comments.

arm-hyp/tk1: address review comments.

arm-hyp/tk1: remove const number

arm-hyp/tk1: make style

arm-hyp/tk1: add default SMMU translation for VM

arm-hyp/tk1: enable SMMU interrupts

arm-hyp/tk1: put iospace caps to bootinfo

arm-hyp/tk1: disable/enable SMMU in secure mode

arm/tk1: a checkpoint for SMMU implementation