x86, mrst: Add dummy legacy pic to platform setup

Moorestown has no legacy PIC; point it to the null legacy PIC.
Signed-off-by: NJacob Pan <jacob.jun.pan@intel.com>
LKML-Reference: <43F901BD926A4E43B106BF17856F07559FB80D09@orsmsx508.amr.corp.intel.com>
Signed-off-by: NH. Peter Anvin <hpa@zytor.com>

arch/x86/kernel/mrst.c

@@ -12,6 +12,9 @@
 #include <linux/init.h>
 
 #include <asm/setup.h>
+#include <asm/mrst.h>
+#include <asm/io.h>
+#include <asm/i8259.h>
 
 /*
  * Moorestown specific x86_init function overrides and early setup
@@ -21,4 +24,6 @@ void __init x86_mrst_early_setup(void)
 {
 	x86_init.resources.probe_roms = x86_init_noop;
 	x86_init.resources.reserve_resources = x86_init_noop;
+
+	legacy_pic = &null_legacy_pic;
 }