dax/hmem: Reduce visibility of dax_cxl coordination symbols

No other module or use case should be using dax_hmem_initial_probe or
dax_hmem_flush_work(). Limit their use to dax_hmem, and dax_cxl
respectively.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Link: https://patch.msgid.link/20260327052821.440749-6-dan.j.williams@intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>

Author: djbw

drivers/dax/hmem/device.c

@@ -9,7 +9,7 @@ static bool nohmem;
 module_param_named(disable, nohmem, bool, 0444);
 
 bool dax_hmem_initial_probe;
-EXPORT_SYMBOL_GPL(dax_hmem_initial_probe);
+EXPORT_SYMBOL_FOR_MODULES(dax_hmem_initial_probe, "dax_hmem");
 
 static bool platform_initialized;
 static DEFINE_MUTEX(hmem_resource_lock);

drivers/dax/hmem/hmem.c

@@ -74,7 +74,7 @@ void dax_hmem_flush_work(void)
 {
 	flush_work(&dax_hmem_work.work);
 }
-EXPORT_SYMBOL_GPL(dax_hmem_flush_work);
+EXPORT_SYMBOL_FOR_MODULES(dax_hmem_flush_work, "dax_cxl");
 
 static int __hmem_register_device(struct device *host, int target_nid,
 				  const struct resource *res)