mips: enable indirect ipc subcall support

* linux/mips/syscallent-n32.h [LINUX_MIPSN32]: Define SYS_socket_subcall,
include "subcall.h".
* linux/mips/syscallent-n64.h [LINUX_MIPSN64]: Likewise.
* linux/mips/syscallent-o32.h [LINUX_MIPSO32]: Likewise.
3 files changed