x86/hyperv: fix a warning in mshyperv.h

The following checkpatch warning is removed:
  WARNING: Use #include <linux/io.h> instead of <asm/io.h>

Signed-off-by: ZhiHu <huzhi001@208suo.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Wei Liu <wei.liu@kernel.org>

Author: ZhiHu

arch/x86/include/asm/mshyperv.h

@@ -5,7 +5,7 @@
 #include <linux/types.h>
 #include <linux/nmi.h>
 #include <linux/msi.h>
-#include <asm/io.h>
+#include <linux/io.h>
 #include <asm/hyperv-tlfs.h>
 #include <asm/nospec-branch.h>
 #include <asm/paravirt.h>