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

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
diff --git a/vgasrc/vgaentry.S b/vgasrc/vgaentry.S
index 112857b..785d91f 100644
--- a/vgasrc/vgaentry.S
+++ b/vgasrc/vgaentry.S
@@ -50,6 +50,11 @@
  * Entry points
  ****************************************************************/
 
+        DECLFUNC entry_104f05
+entry_104f05:
+        ENTRY_ARG vbe_104f05
+        lretw
+
         DECLFUNC _optionrom_entry
 _optionrom_entry:
         ENTRY_ARG vga_post