test: exercise secure espi interrupt handling

Hafnium/SPMC added support for enabling interrupts in the extended SPI
range. With the help of an SiP SMC call that can pend an interrupt,
this patch adds a test to trigger an espi interrupt when cactus is
running and ensure it is handled.

Additionally, a dummy device region node representing a fake
peripheral has been added to the Cactus SP manifest. It is used to
specify properties of the interrupt in the extended SPI range used
for the above test scenario.

Signed-off-by: Raghu Krishnamurthy <raghu.ncstate@gmail.com>
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
Change-Id: Ief932c40e3abd33d619f2b144e61cae449147b27
7 files changed