Add psputility error code definitions

https://github.com/hrydgard/ppsspp/issues/13187#issuecomment-680941546

src/utility/psputility_modules.h

@@ -52,6 +52,8 @@ extern "C" {
 /* IrDA */
 #define PSP_MODULE_IRDA				0x0600
 
+/** An error code used as a return value */
+#define SCE_ERROR_MODULE_ALREADY_LOADED (0x80111102)
 
 /**
  * Load a module (PRX) from user mode.

src/utility/psputility_netmodules.h

@@ -24,6 +24,9 @@ extern "C" {
 #define PSP_NET_MODULE_PARSEHTTP 5
 #define PSP_NET_MODULE_HTTP 6
 #define PSP_NET_MODULE_SSL 7
+    
+/** An error code used as a return value */
+#define SCE_ERROR_NET_MODULE_NOT_LOADED (0x80110803)
 
 /**
  * Load a network module (PRX) from user mode.