opae.io: include unistd.h

This is needed for pread() and pwrite(). The missing header became
apparent due to a build failure with Python 3.13.0a1 which no longer
included unistd.h itself, but that change has since been reverted.

Link: https://bugzilla.redhat.com/2247016
Signed-off-by: Peter Colberg <peter.colberg@intel.com>

binaries/opae.io/main.h

@@ -27,6 +27,7 @@
 #pragma once
 
 #include <iostream>
+#include <unistd.h>
 #include <sys/ioctl.h>
 #include <opae/vfio.h>