util/spd_tools: Add support for Phoenix platform

Update spd_gen and part_id_gen utilities to accommodate Phoenix platform
so that SPD can be generated for the memory parts used in that platform.
SPD requirements for Phoenix and Mendocino platforms are identical.

BUG=b:273383819
TEST=Run spd_gen and ensure that both Mendocino and Phoenix platforms
share the platform manifest for LP5 memory parts.

Change-Id: I7a12f73065864f08db8922c1a69eb503865a25b1
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/74125
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jon Murphy <jpmurphy@google.com>

spd/lp5/platforms_manifest.generated.txt

@@ -3,4 +3,5 @@
 
 MTL,set-0
 ADL,set-0
+PHX,set-1
 MDN,set-1

util/spd_tools/src/part_id_gen/part_id_gen.go

@@ -42,6 +42,7 @@ var supportedPlatforms = [...]string{
 	"CZN",
 	"MDN",
 	"MTL",
+	"PHX",
 }
 
 var supportedMemTechs = [...]string{

util/spd_tools/src/spd_gen/lp5.go

@@ -177,7 +177,7 @@ const (
 
 var LP5PlatformSetMap = map[int][]int{
 	0: {PlatformMTL, PlatformADL},
-	1: {PlatformMDN},
+	1: {PlatformPHX, PlatformMDN},
 }
 
 var LP5SetInfo = map[int]LP5Set{

util/spd_tools/src/spd_gen/spd_gen.go

@@ -74,6 +74,7 @@ const (
 	PlatformCZN
 	PlatformMDN
 	PlatformMTL
+	PlatformPHX
 	PlatformMax
 )
 
@@ -94,6 +95,7 @@ var platformNames = map[int]string{
 	PlatformCZN: "CZN",
 	PlatformMDN: "MDN",
 	PlatformMTL: "MTL",
+	PlatformPHX: "PHX",
 }
 
 var memTechMap = map[string]memTech{