vgabios: Add support for vesa get/set window function.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/vgasrc/bochsvga.h b/vgasrc/bochsvga.h
index 1eaa91a..26a82e0 100644
--- a/vgasrc/bochsvga.h
+++ b/vgasrc/bochsvga.h
@@ -55,6 +55,8 @@
 int bochsvga_init(void);
 void bochsvga_list_modes(u16 seg, u16 *dest, u16 *last);
 struct vgamode_s *bochsvga_find_mode(int mode);
+int bochsvga_get_window(struct vgamode_s *vmode_g, int window);
+int bochsvga_set_window(struct vgamode_s *vmode_g, int window, int val);
 int bochsvga_set_mode(struct vgamode_s *vmode_g, int flags);
 
 #endif // bochsvga.h