Improve DIMM detection for AMCC Yucca 440SPe board

Improved the memory DIMM detection for the Yucca 440SPe board for
the case where a memory DIMM is falsely detected as present.

This issue is seen on some AMCC Yucca 440SPe validation boards if
only one 512MB memory DIMM is installed, i.e. DIMM slot 0 is
populated and DIMM slot 1 is empty.  In this case, U-Boot does
not correctly detect that there is only one DIMM memory module
installed and will falsely detect two DIMM memory modules are
present and therefore U-Boot will not calculate the correct amount
of total memory and u-boot will not booting up.

Patch by Adam Graham, 24 Aug 2006
diff --git a/board/amcc/yucca/yucca.h b/board/amcc/yucca/yucca.h
index 66f7584..4d13021 100644
--- a/board/amcc/yucca/yucca.h
+++ b/board/amcc/yucca/yucca.h
@@ -60,6 +60,9 @@
 
 #define NUM_TLB_ENTRIES          64
 
+/* MICRON SPD JEDEC ID Code (first byte) - SPD data byte [64] */
+#define MICRON_SPD_JEDEC_ID 0x2c
+
 /*----------------------------------------------------------------------------+
 | TLB specific defines.
 +----------------------------------------------------------------------------*/