ARC: remove extraneous __KERNEL__ guards

Verified by doing make headers_install as none of these files are
exported to userspace

arch/arc/include/asm/irqflags.h

@@ -15,8 +15,6 @@
  *  -Conditionally disable interrupts (if they are not enabled, don't disable)
 */
 
-#ifdef __KERNEL__
-
 #include <asm/arcregs.h>
 
 /* status32 Reg bits related to Interrupt Handling */
@@ -169,6 +167,4 @@ static inline int arch_irqs_disabled(void)
 
 #endif	/* __ASSEMBLY__ */
 
-#endif	/* KERNEL */
-
 #endif