[HACK] Platform/Sgi: add hacks to inject dram errors to DMC

DMC only supports SRAM error injection via integ_cfg registers. So these
hacks added will catch the SRAM error injection events and convert them
to DRAM errors, by programming appropriate DRAM error record registers.

Signed-off-by: Omkar Anand Kulkarni <omkar.kulkarni@arm.com>
Change-Id: Ifdcb4d14bd2fb11d41b8a80cc8731dd941deced7