trusty: qemu: specify IPIs in new way

Some IRQs that are received by Linux need to be intercepted by the
Trusty driver and forwarded to Trusty.  For this to work, the
device-tree node for the trusty-irq "device" needs to specify which
Linux IRQs correspond to which secure IRQs.

Some of these IRQs are IPIs ("inter-processor interrupts").  But since
IPIs previously weren't normal Linux IRQs, the Trusty kernel branches
have been carrying a patch "ANDROID: arm64: smp: Add support for custom
ipi interrupt handlers" (http://aosp/1343165) to expose specific IPIs
via a "CustomIPI" irq_chip.

This approach for specifying IPIs is being replaced with one based on
the patchset "arm/arm64: Turning IPIs into normal interrupts"
(https://lkml.kernel.org/lkml/20200901144324.1071694-1-maz@kernel.org),
which hopefully will make it into Linux 5.10.

Make the device tree changes needed for the new approach.

Change-Id: I6678da4bec18096b8517030952dbb4625282f0ce
1 file changed