MIPS: compat: Implement is_compat_task.

This is a build fix required after "x86-64: seccomp: fix 32/64 syscall
hole" (commit 5b1017404aea6d2e552e991b3fd814d839e9cd67).  MIPS doesn't
have the issue that was fixed for x86-64 by that patch.

This also doesn't solve the N32 issue which is that N32 seccomp processes
will be treated as non-compat processes thus only have access to N64
syscalls.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/mips/include/asm/compat.h

@@ -3,6 +3,8 @@
 /*
  * Architecture specific compatibility types
  */
+#include <linux/seccomp.h>
+#include <linux/thread_info.h>
 #include <linux/types.h>
 #include <asm/page.h>
 #include <asm/ptrace.h>
@@ -218,4 +220,9 @@ struct compat_shmid64_ds {
 	compat_ulong_t	__unused2;
 };
 
+static inline int is_compat_task(void)
+{
+	return test_thread_flag(TIF_32BIT);
+}
+
 #endif /* _ASM_COMPAT_H */