parisc: Avoid compiler warning for handle_16()

Signed-off-by: Helge Deller <deller@gmx.de>
diff --git a/src/parisc/lasips2.c b/src/parisc/lasips2.c
index a7bb9fe..b7d0083 100644
--- a/src/parisc/lasips2.c
+++ b/src/parisc/lasips2.c
@@ -26,6 +26,7 @@
     }
 
     while(count < max) {
+        extern void VISIBLE16 handle_16(struct bregs *regs);
         // check if some key is queued up already
         regs.ah = 0x11;
         regs.flags = 0;