vfio: fix include with musl runtime

[ upstream commit c41a103c961ded5a0966652f4daf0a661a947352 ]

pread64() and pwrite64() are declared in <unistd.h> in MUSL and
other (i.e. not glibc) C runtimes.

Signed-off-by: Philip Prindeville <philipp@redfish-solutions.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>

.mailmap

@@ -1050,6 +1050,7 @@ Peter Spreadborough <peter.spreadborough@broadcom.com>
 Petr Houska <t-pehous@microsoft.com>
 Phanendra Vukkisala <pvukkisala@marvell.com>
 Phil Yang <phil.yang@arm.com>
+Philip Prindeville <philipp@redfish-solutions.com>
 Pierre Pfister <ppfister@cisco.com>
 Piotr Azarewicz <piotr.azarewicz@intel.com> <piotrx.t.azarewicz@intel.com>
 Piotr Bartosiewicz <piotr.bartosiewicz@atendesoftware.pl>

drivers/bus/pci/linux/pci_vfio.c

@@ -2,6 +2,7 @@
  * Copyright(c) 2010-2014 Intel Corporation
  */
 
+#include <unistd.h>
 #include <string.h>
 #include <fcntl.h>
 #include <linux/pci_regs.h>