[PATCH] x86-64: Fix allnoconfig error in genapic_flat.c

Fix:

In file included from include2/asm/apic.h:5,
                 from include2/asm/smp.h:15,
                 from linux/arch/x86_64/kernel/genapic_flat.c:18:
linux/include/linux/pm.h: In function ‘call_platform_enable_wakeup’:
linux/include/linux/pm.h:331: error: ‘EIO’ undeclared (first use in this function)
linux/include/linux/pm.h:331: error: (Each undeclared identifier is reported only once
linux/include/linux/pm.h:331: error: for each function it appears in.)

Signed-off-by: Andi Kleen <ak@suse.de>

arch/x86_64/kernel/genapic_flat.c

@@ -8,6 +8,7 @@
  * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and
  * James Cleverdon.
  */
+#include <linux/errno.h>
 #include <linux/threads.h>
 #include <linux/cpumask.h>
 #include <linux/string.h>