arm64: Call EDAC error handler on system error

One possible cause of a system error exception is an ECC
error in the CPU's caches. Call the ARM64 EDAC error
handler from the system error exception handler to print
EDAC error syndrome information to the kernel log.

Change-Id: If8757eda0c7fc82b0fccee573cf09627a752fdf3
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>