cxl/core: Drop is_cxl_decoder()

This helper was only used to identify the object type for lockdep
purposes. Now that lockdep support is done with explicit lock classes,
this helper can be dropped.
Reviewed-by: Alison Schofield <alison.schofield@intel.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Adam Manzanares <a.manzanares@samsung.com>
Link: https://lore.kernel.org/r/165603874340.551046.15491766127759244728.stgit@dwillia2-xfhSigned-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/cxl/core/port.c

@@ -271,12 +271,6 @@ bool is_root_decoder(struct device *dev)
 }
 EXPORT_SYMBOL_NS_GPL(is_root_decoder, CXL);
 
-bool is_cxl_decoder(struct device *dev)
-{
-	return dev->type && dev->type->release == cxl_decoder_release;
-}
-EXPORT_SYMBOL_NS_GPL(is_cxl_decoder, CXL);
-
 struct cxl_decoder *to_cxl_decoder(struct device *dev)
 {
 	if (dev_WARN_ONCE(dev, dev->type->release != cxl_decoder_release,

drivers/cxl/cxl.h

@@ -337,7 +337,6 @@ struct cxl_dport *cxl_find_dport_by_dev(struct cxl_port *port,
 struct cxl_decoder *to_cxl_decoder(struct device *dev);
 bool is_root_decoder(struct device *dev);
 bool is_endpoint_decoder(struct device *dev);
-bool is_cxl_decoder(struct device *dev);
 struct cxl_decoder *cxl_root_decoder_alloc(struct cxl_port *port,
 					   unsigned int nr_targets);
 struct cxl_decoder *cxl_switch_decoder_alloc(struct cxl_port *port,