nb/amd/mct_ddr3: Enable DIMM parity when RDIMMs installed

This resolves a long-standing issue with RDIMM control word
configuration failure, likely due to random parity failure.

Change-Id: If8b8dc5b8b99f4c2fe29b3a133b064631e4693be
Signed-off-by: Timothy Pearson <tpearson@raptorengineeringinc.com>
Reviewed-on: https://review.coreboot.org/14184
Tested-by: build bot (Jenkins)
Tested-by: Raptor Engineering Automated Test Stand <noreply@raptorengineeringinc.com>
Reviewed-by: Martin Roth <martinroth@google.com>

src/northbridge/amd/amdmct/mct_ddr3/mct_d.c

@@ -5124,9 +5124,7 @@ static u8 AutoConfig_D(struct MCTStatStruc *pMCTstat,
 
 	if (Status & (1 << SB_Registered)) {
 		/* Registered DIMMs */
-		if (!is_fam15h()) {
-			DramConfigLo |= 1 << ParEn;
-		}
+		DramConfigLo |= 1 << ParEn;
 	} else {
 		/* Unbuffered DIMMs */
 		DramConfigLo |= 1 << UnBuffDimm;