[XTENSA] Fix fadvise64_64

Xtensa passes long long arguments in a even/odd register pair,
so we also need to shuffle the arguments when passed through the
system call to avoid an empty argument register.

Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/include/asm-xtensa/syscall.h b/include/asm-xtensa/syscall.h
index ea9b513..05cebf8 100644
--- a/include/asm-xtensa/syscall.h
+++ b/include/asm-xtensa/syscall.h
@@ -28,6 +28,8 @@
 				 struct sigaction __user *,
 				 size_t);
 asmlinkage long xtensa_shmat(int, char __user *, int);
+asmlinkage long xtensa_fadvise64_64(int, int,
+				    unsigned long long, unsigned long long);
 
 /* Should probably move to linux/syscalls.h */
 struct pollfd;