Add Linux DTS files for 32 bit threaded FVPs ...

RevC models have the MT bit set and the affinities shifted in the MPIDR
register. To make the Linux able to boot all CPUs it needs a modified
DTS file containing the shifted affinity values.

Beside these values the DTS files should be the same so the common part
was moved into a new file which is included in the DTS files with
shifted and non-shifted affinities.

The same setup already exists for 64 bit systems.

Signed-off-by: Imre Kis <imre.kis@arm.com>
Change-Id: I90f7b9c8d8a24c9b3f97232441dbe0a29aa8976d

FVP: Fix AArch32 dts for `interrupts` node ...

The commit 8d2c497 changed the interrupt map in `rtsm_ve-motherboard.dtsi`
for the Linux FDT sources to be compatible for FreeBSD. But this also
introduced a regression for FVP AArch32 mode but was undetected till now
because the corresponding DTB was not updated. This patch creates a
new `rtsm_ve-motherboard-aarch32.dtsi` which reverts the change and is
now included by the AArch32 DTS files.

Change-Id: Ibefbbf43a91c8fb890f0fa7a22be91f0227dad34
Signed-off-by: Soby Mathew <soby.mathew@arm.com>

Device tree changes to boot FreeBSD on FVPs ...

FreeBSD does not understand #interrupt-map in a device tree. This prevents the
GIC from being set up correctly. This patch removes the #interrupt-map in the
device trees for the Base and Foundation FVPs. This enables correct boot of
FreeBSD on these platforms.

These changes have been tested with FreeBSD and an Ubuntu cloud image
(ubuntu-16.04-server-cloudimg-arm64-uefi1.img) to ensure compatibility with
Linux.

Change-Id: I1347acdcf994ec4b1dd843ba32af9951aa54db73
Signed-off-by: Achin Gupta <achin.gupta@arm.com>

AArch32: Update user-guide and add DTBs ...

This patch adds necessary updates for building and running Trusted
Firmware for AArch32 to user-guide.md. The instructions for running
on both `FVP_Base_AEMv8A-AEMv8A` in AArch32 mode and
`FVP_Base_Cortex-A32x4` models are added. The device tree files for
AArch32 Linux kernel are also added in the `fdts` folder.

Change-Id: I0023b6b03e05f32637cb5765fdeda8c8df2d0d3e