edac: edac_mc_handle_error(): add an error_count parameter

In order to avoid loosing error events, it is desirable to group
error events together and generate a single trace for several identical
errors.

The trace API already allows reporting multiple errors. Change the
handle_error function to also allow that.

The changes at the drivers were made by this small script:

	$file .=$_ while (<>);
	$file =~ s/(edac_mc_handle_error)\s*\(([^\,]+)\,([^\,]+)\,/$1($2,$3, 1,/g;
	print $file;

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>