mpc8xxx: DDR2/DDR3: Clean up DIMM-type switch statements

The numeric constants in the switch statements are replaced by #defines
added to the common ddr_spd.h header.  This dramatically improves the
readability of the switch statments.

In addition, a few of the longer lines were cleaned up, and the DDR2
type for an SO-RDIMM module was added to the DDR2 switch statement.

Signed-off-by: Kyle Moffett <Kyle.D.Moffett@boeing.com>
Cc: Andy Fleming <afleming@gmail.com>
Cc: Kim Phillips <kim.phillips@freescale.com>
Acked-by: York Sun <yorksun@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/common/ddr_spd.c b/common/ddr_spd.c
index a7a30de..7a388bb 100644
--- a/common/ddr_spd.c
+++ b/common/ddr_spd.c
@@ -18,7 +18,7 @@
 
 	/*
 	 * Check SPD revision supported
-	 * Rev 1.2 or less supported by this code
+	 * Rev 1.X or less supported by this code
 	 */
 	if (spd_rev >= 0x20) {
 		printf("SPD revision %02X not supported by this code\n",