vgabios: Simplify save/restore mechanism.

Reorganize the save/restore functions to eliminate some boilerplate
code.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/vgasrc/clext.h b/vgasrc/clext.h
index efc98b9..cf47a5b 100644
--- a/vgasrc/clext.h
+++ b/vgasrc/clext.h
@@ -11,9 +11,7 @@
 int clext_set_linelength(struct vgamode_s *vmode_g, int val);
 int clext_get_displaystart(struct vgamode_s *vmode_g);
 int clext_set_displaystart(struct vgamode_s *vmode_g, int val);
-int clext_size_state(int states);
-int clext_save_state(u16 seg, void *data, int states);
-int clext_restore_state(u16 seg, void *data, int states);
+int clext_save_restore(int cmd, u16 seg, void *data);
 int clext_set_mode(struct vgamode_s *vmode_g, int flags);
 struct bregs;
 void clext_1012(struct bregs *regs);