[MiNT] remove psignal definition from unistd.h

[Alan Hourihane <alanh@fairlite.demon.co.uk>]

Patch to remove from unistd.h as it's defined in signal.h and the
definition differs because of __THROW.

Alan.

Index: include/unistd.h
===================================================================
RCS file: /mint/mintlib/include/unistd.h,v
retrieving revision 1.11
diff -u -r1.11 unistd.h
--- include/unistd.h	6 Dec 2005 19:08:17 -0000	1.11
+++ include/unistd.h	15 Jun 2008 18:50:20 -0000
@@ -1033,7 +1031,6 @@
 extern long random (void) __THROW;
 extern void srandom (unsigned int seed) __THROW;
 
-extern void psignal (int, const char *) __THROW;
 extern long tell (int) __THROW;