Build fixes for struct pt_regs removal

Signed-off-by: Matthew Wilcox <matthew@wil.cx>
diff --git a/include/asm-parisc/irq_regs.h b/include/asm-parisc/irq_regs.h
new file mode 100644
index 0000000..3dd9c0b
--- /dev/null
+++ b/include/asm-parisc/irq_regs.h
@@ -0,0 +1 @@
+#include <asm-generic/irq_regs.h>