Fix compilation error with musl-based toolchain

linux_sysfs.c:751:15: error: 'PATH_MAX' undeclared (first use in this function)
     char name[PATH_MAX];

Patch already sent upstream by Felix Janda
http://lists.x.org/archives/xorg-devel/2014-December/044723.html

Signed-off-by: Felix Janda <felix.janda at posteo.de>
Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>

diff -uNr libpciaccess-0.13.3.org/src/linux_sysfs.c libpciaccess-0.13.3/src/linux_sysfs.c
--- libpciaccess-0.13.3.org/src/linux_sysfs.c	2015-02-04 00:59:14.000000000 +0100
+++ libpciaccess-0.13.3/src/linux_sysfs.c	2015-04-10 21:57:35.000000000 +0200
@@ -44,6 +44,7 @@
 #include <sys/mman.h>
 #include <dirent.h>
 #include <errno.h>
+#include <limits.h>
 
 #if defined(__i386__) || defined(__x86_64__) || defined(__arm__)
 #include <sys/io.h>