cdx: Create resource debugfs file for cdx device

resource debugfs file contains host addresses of CDX device resources.
Each line of the resource file describe type of resource, a region
with start-end and flag fields.

Signed-off-by: Abhijit Gangurde <abhijit.gangurde@amd.com>
Link: https://lore.kernel.org/r/20231222064627.2828960-2-abhijit.gangurde@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/cdx/cdx_bus.h

@@ -113,6 +113,7 @@ struct cdx_controller {
  * @dev_num: Device number for this device
  * @res: array of MMIO region entries
  * @res_attr: resource binary attribute
+ * @debugfs_dir: debugfs directory for this device
  * @res_count: number of valid MMIO regions
  * @dma_mask: Default DMA mask
  * @flags: CDX device flags
@@ -136,6 +137,7 @@ struct cdx_device {
 	u8 dev_num;
 	struct resource res[MAX_CDX_DEV_RESOURCES];
 	struct bin_attribute *res_attr[MAX_CDX_DEV_RESOURCES];
+	struct dentry *debugfs_dir;
 	u8 res_count;
 	u64 dma_mask;
 	u16 flags;