powerpc: Wire up statx() syscall

Test runs on a ppc64 BE guest succeeded. linux/samples/statx/test-statx
program was executed on the following file types,

1. Regular file
2. Directory
3. device file
4. symlink
5. Named pipe

The test run also included invoking test-statx with the runtime options
provided in the main() function of test-statx.c
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

@@ -387,3 +387,4 @@ SYSCALL(copy_file_range)
 COMPAT_SYS_SPU(preadv2)
 COMPAT_SYS_SPU(pwritev2)
 SYSCALL(kexec_file_load)
+SYSCALL(statx)

arch/powerpc/include/asm/unistd.h

@@ -12,7 +12,7 @@
 #include <uapi/asm/unistd.h>
 
 
-#define NR_syscalls		383
+#define NR_syscalls		384
 
 #define __NR__exit __NR_exit
 

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

@@ -393,5 +393,6 @@
 #define __NR_preadv2		380
 #define __NR_pwritev2		381
 #define __NR_kexec_file_load	382
+#define __NR_statx		383
 
 #endif /* _UAPI_ASM_POWERPC_UNISTD_H_ */