MIPS: Enable entries for SIGSYS in struct siginfo.

This is necessary because MIPS doesn't use HAVE_ARCH_SIGINFO_T for
historical reasons.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/uapi/asm/siginfo.h

@@ -33,6 +33,8 @@ struct siginfo;
 #error _MIPS_SZLONG neither 32 nor 64
 #endif
 
+#define __ARCH_SIGSYS
+
 #include <asm-generic/siginfo.h>
 
 typedef struct siginfo {
@@ -97,6 +99,13 @@ typedef struct siginfo {
 			__ARCH_SI_BAND_T _band; /* POLL_IN, POLL_OUT, POLL_MSG */
 			int _fd;
 		} _sigpoll;
+
+		/* SIGSYS */
+		struct {
+			void __user *_call_addr; /* calling user insn */
+			int _syscall;	/* triggering system call number */
+			unsigned int _arch;	/* AUDIT_ARCH_* of syscall */
+		} _sigsys;
 	} _sifields;
 } siginfo_t;