[fusl] Remove code for unsupported architectures

fusl/arch/mips/ksigaction.h

Index: fusl/arch/mips/ksigaction.h
diff --git a/fusl/arch/mips/ksigaction.h b/fusl/arch/mips/ksigaction.h
deleted file mode 100644
index 9170bcff76419696889b3fd46344c259bbc8e0fb..0000000000000000000000000000000000000000
--- a/fusl/arch/mips/ksigaction.h
+++ /dev/null
@@ -1,11 +0,0 @@
-struct k_sigaction {
-  unsigned flags;
-  void (*handler)(int);
-  unsigned long mask[4];
-  /* The following field is past the end of the structure the
-   * kernel will read or write, and exists only to avoid having
-   * mips-specific preprocessor conditionals in sigaction.c. */
-  void (*restorer)();
-};
-
-void __restore(), __restore_rt();