docs(spm): update threat model

Update SPM threat model for possible threats, from malicious
endpoints, related to interrupt management. The mitigations
are based on the guidance provided in FF-A v1.1 EAC0 spec.

Change-Id: Ib9e26e3f1c60fe3a2734a67de1dcf1cea4883d38
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>
1 file changed