vgabios: Use vgamode_s in cirrus and bochsvga mode tables.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/vgasrc/clext.h b/vgasrc/clext.h
index 6fd0a58..e344639 100644
--- a/vgasrc/clext.h
+++ b/vgasrc/clext.h
@@ -3,6 +3,7 @@
 
 #include "types.h" // u8
 
+struct vgamode_s *clext_find_mode(int mode);
 int clext_set_mode(int mode, int flags);
 int clext_init(void);