plat/sgi: tag dmc620 MM communicate messages with a guid

Define a GUID that should be used in the header of MM communicate
message originating due to a dmc620 ECC error interrupt. So the use
of SMC ID in 'sgi_ras_ev_map' to represent the interrupt event is
removed.

In addition to this, update the dmc620 error record data structure to
use aux_data to indicate the dmc620 instance number on which the ECC
error interrupt occurred.

Signed-off-by: Omkar Anand Kulkarni <omkar.kulkarni@arm.com>
Change-Id: I18c8ef5ba6483bb1bce6464ee9be0c2aabec4baa
2 files changed