PPC32: Add the fadvise64_64 system call.

On PPC32 we reorder the arguments so they fit into 6 registers.  Glibc will
need a two-line stub to change them from the standard order to the ordering
used by the system call: (fd, advice, offset, len).

arch/ppc/kernel/misc.S

@@ -1380,3 +1380,4 @@ _GLOBAL(sys_call_table)
 	.long sys_utimes
 	.long sys_statfs64
 	.long sys_fstatfs64
+	.long ppc_fadvise64_64

arch/ppc/kernel/syscalls.c

@@ -262,4 +262,14 @@ int sys_olduname(struct oldold_utsname __user * name)
 	return error;
 }
 
+/*
+ * We put the arguments in a different order so we only use 6
+ * registers for arguments, rather than 7 as sys_fadvise64_64 needs
+ * (because `offset' goes in r5/r6).
+ */
+long ppc_fadvise64_64(int fd, int advice, loff_t offset, loff_t len)
+{
+	return sys_fadvise64_64(fd, offset, len, advice);
+}
+
 cond_syscall(sys_pciconfig_iobase);

include/asm-ppc/unistd.h

@@ -258,8 +258,9 @@
 #define __NR_utimes		251
 #define __NR_statfs64		252
 #define __NR_fstatfs64		253
+#define __NR_fadvise64_64	254
 
-#define __NR_syscalls		254
+#define __NR_syscalls		255
 
 #define __NR(n)	#n