Some headers are not needed since the driver can be built as module.
Remove them.

While here, sort headers alphabetically.
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: NDarren Hart (VMware) <dvhart@infradead.org>
Signed-off-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>