nvme: add accessor to namespace id and eui64

This adds a function which can be used by e.g. EFI to retrieve
the namespace identifier and EUI64.  For that it adds the EUI64
to its driver internal namespace structure and copies the EUI64
during namespace identification.

Signed-off-by: Patrick Wildt <patrick@blueri.se>
Tested-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

include/nvme.h

@@ -78,4 +78,16 @@ int nvme_scan_namespace(void);
  */
 int nvme_print_info(struct udevice *udev);
 
+/**
+ * nvme_get_namespace_id - return namespace identifier
+ *
+ * This returns the namespace identifier.
+ *
+ * @udev:	NVMe controller device
+ * @ns_id:	Place where to put the name space identifier
+ * @eui64:	Place where to put the IEEE Extended Unique Identifier
+ * @return:	0 on success, -ve on error
+ */
+int nvme_get_namespace_id(struct udevice *udev, u32 *ns_id, u8 *eui64);
+
 #endif /* __NVME_H__ */