xtensa: disable socket and ipc subcall support

The Xtensa architecture also uses dedicated syscalls and doesn't
need to multiplex ipc and socket subcalls.

* linux/syscall.h [XTENSA]: Do not define SYS_socket_subcall and
SYS_ipc_subcall.

Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/linux/syscall.h b/linux/syscall.h
index d0cf423..878732d 100644
--- a/linux/syscall.h
+++ b/linux/syscall.h
@@ -318,7 +318,8 @@
  && !defined(HPPA) \
  && !defined(__ARM_EABI__) \
  && !defined(BFIN) \
- && !defined(TILE)
+ && !defined(TILE) \
+ && !defined(XTENSA)
 # if defined(SPARC) || defined(SPARC64)
 #  define SYS_socket_subcall	353
 # else