nb/intel/i945: Refactor `dump_spd_registers` function

Use the mainboard-provided SPD map and skip unused addresses.

Change-Id: I2b5b71cff290343c1000d5613209049fa9724e3d
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51899
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>
diff --git a/src/northbridge/intel/i945/romstage.c b/src/northbridge/intel/i945/romstage.c
index 248fe14..22eae4e 100644
--- a/src/northbridge/intel/i945/romstage.c
+++ b/src/northbridge/intel/i945/romstage.c
@@ -48,11 +48,11 @@
 
 	mainboard_pre_raminit_config(s3resume);
 
-	if (CONFIG(DEBUG_RAM_SETUP))
-		dump_spd_registers();
-
 	mainboard_get_spd_map(spd_map);
 
+	if (CONFIG(DEBUG_RAM_SETUP))
+		dump_spd_registers(spd_map);
+
 	sdram_initialize(s3resume ? BOOT_PATH_RESUME : BOOT_PATH_NORMAL, spd_map);
 
 	/* This should probably go away. Until now it is required