kernel: Add more architecture code post-scheduler

* Fix incorrect cpu vendor name mapping
* Add additional CPU architectures
* Add additional CPU vendors
* Rework PowerPC arch_system_info passing
  PVR back for cpu model

headers/private/shared/cpu_type.h

@@ -170,8 +170,10 @@ parse_amd(const char* name)
 static const char*
 get_cpu_vendor_string(enum cpu_vendor cpuVendor)
 {
+	// Should match vendors in OS.h
 	static const char* vendorStrings[] = {
-		NULL, "AMD", "Cyrix", "IDT", "Intel", "Rise", "Transmeta", "VIA",
+		NULL, "AMD", "Cyrix", "IDT", "Intel", "National Semiconductor", "Rise",
+		"Transmeta", "VIA", "IBM", "Motorola", "NEC"
 	};
 
 	if ((size_t)cpuVendor >= sizeof(vendorStrings) / sizeof(const char*))