firmware: test_ffa: Add Test FFA driver

Add a test driver on top of the FF-A Driver to exercise
a Physical and Logical SP via the EL3 SPMC.

This driver requires a userspace application to be added
to the linux filesystem to allow communication with the driver.

The following tests are available:

1) Echo a message to the Physical SP and Back using direct req/resp
2) Send a direct request to the physical SP and ask it to send it's
   own direct_req to the Logical SP and relay the message back again.
3) Share a single page of memory with the SP and ensure the contents
   can be modified.
4) Share multiple pages requiring the memory descriptor to be split
   over multiple invocations.
5) Lend a single page of memory with the SP and ensure the contents
   can be modified.
6) Lend multiple pages requiring the memory descriptor to be split
   over multiple invocations.
255) Run all of the above test cases.

Signed-off-by: Marc Bonnici <marc.bonnici@arm.com>
2 files changed