Platform/Sgi: Add EINJ trigger error action table

EINJ ACPI table mandates at least one entry of trigger error action
table be present. To suffice this add one instruction entry to trigger
error action table. Also set the EINJ buffer memory region to 0.

Change-Id: Idf2af8216ceb5aa4e6edc6eed9b502fc21e4f3cb
Signed-off-by: Omkar Anand Kulkarni <omkar.kulkarni@arm.com>