[SETUPLIB] Make the settings' Process* functions take an actual value instead of a GENERIC_LIST

The reason is to avoid enforcing the usage of a specific list
container by the users of the setup library. This is a departure
of what I originally thought would be the best, in commits
92692eae3 (r74553), 8f2c4f7a6 (r75700)

This should actually make some parts of the GUI setup code simpler
(e.g. using the win32 comboboxes to store the list contents).

base/setup/lib/setuplib.h

@@ -122,6 +122,13 @@ typedef struct _USETUP_DATA
     PGENERIC_LIST LayoutList;
     PGENERIC_LIST LanguageList;
 
+/* Settings *****/
+    PCWSTR ComputerType;
+    PCWSTR DisplayType;
+    // PCWSTR KeyboardDriver;
+    // PCWSTR MouseDriver;
+    PCWSTR LayoutId; // DefaultKBLayout
+
 /* Other stuff *****/
     WCHAR LocaleID[9];
     LANGID LanguageId;