powerpc: Wire up copy_file_range() syscall

Test runs on a ppc64 BE guest succeeded using modified fstests.

Also tested on ppc64 LE using a home made test - mpe.
Signed-off-by: NChandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/systbl.h

@@ -383,3 +383,4 @@ SYSCALL(ni_syscall)
 SYSCALL(ni_syscall)
 SYSCALL(ni_syscall)
 SYSCALL(mlock2)
+SYSCALL(copy_file_range)

arch/powerpc/include/asm/unistd.h

@@ -12,7 +12,7 @@
 #include <uapi/asm/unistd.h>
 
 
-#define NR_syscalls		379
+#define NR_syscalls		380
 
 #define __NR__exit __NR_exit
 

arch/powerpc/include/uapi/asm/unistd.h

@@ -389,5 +389,6 @@
 #define __NR_userfaultfd	364
 #define __NR_membarrier		365
 #define __NR_mlock2		378
+#define __NR_copy_file_range	379
 
 #endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */