Impact: cleanup

Fix:

 WARNING: Use #include <linux/nmi.h> instead of <asm/nmi.h>
 WARNING: Use #include <linux/smp.h> instead of <asm/smp.h>
 WARNING: Use #include <linux/io.h> instead of <asm/io.h>

 total: 0 errors, 3 warnings
Signed-off-by: NJaswinder Singh Rajput <jaswinderrajput@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>