cxl: Include range.h in cxl.h

cxl: Include range.h in cxl.h

After commit aefeb286b960 ("libnvdimm: Don't use "proxy" headers"),
range.h may not be implicitly included, resulting in a build error:

  In file included from drivers/cxl/core/features.c:8:
  drivers/cxl/cxl.h:365:22: error: field 'hpa_range' has incomplete type
    365 |         struct range hpa_range;
        |                      ^~~~~~~~~
  drivers/cxl/cxl.h:562:22: error: field 'hpa_range' has incomplete type
    562 |         struct range hpa_range;
        |                      ^~~~~~~~~
  drivers/cxl/cxl.h:570:22: error: field 'hpa_range' has incomplete type
    570 |         struct range hpa_range;
        |                      ^~~~~~~~~
  drivers/cxl/cxl.h:803:22: error: array type has incomplete element type 'struct range'
    803 |         struct range dvsec_range[2];
        |                      ^~~~~~~~~~~

Include range.h in cxl.h explicitly to clear up the errors.

Fixes: aefeb286b960 ("libnvdimm: Don't use "proxy" headers")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20250701-cxl-fix-struct-range-error-v1-1-1f199bddc7c9@kernel.org
Signed-off-by: Ira Weiny <ira.weiny@intel.com>