x86/entry: __always_inline irqflags for noinstr

vmlinux.o: warning: objtool: lockdep_hardirqs_on()+0x65: call to arch_local_save_flags() leaves .noinstr.text section
vmlinux.o: warning: objtool: lockdep_hardirqs_off()+0x5d: call to arch_local_save_flags() leaves .noinstr.text section
vmlinux.o: warning: objtool: lock_is_held_type()+0x35: call to arch_local_irq_save() leaves .noinstr.text section
vmlinux.o: warning: objtool: check_preemption_disabled()+0x31: call to arch_local_save_flags() leaves .noinstr.text section
vmlinux.o: warning: objtool: check_preemption_disabled()+0x33: call to arch_irqs_disabled_flags() leaves .noinstr.text section
vmlinux.o: warning: objtool: lock_is_held_type()+0x2f: call to native_irq_disable() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200603114052.012171668@infradead.org