nvme: Get rid of the global variable nvme_info

At present the NVMe uclass driver uses a global variable nvme_info
to store global information like namespace id, and NVMe controller
driver's priv struct has a blk_dev_start that is used to calculate
the namespace id based on the global information from nvme_info.

This is not a good design in the DM world and can be replaced with
the following changes:

- Encode the namespace id in the NVMe block device name during
  the NVMe uclass post probe
- Extract the namespace id from the device name during the NVMe
  block device probe
- Let BLK uclass calculate the devnum for us by passing -1 to
  blk_create_devicef() as the devnum

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/nvme/nvme.c b/drivers/nvme/nvme.c
index 67f7d75..ec32d0d 100644
--- a/drivers/nvme/nvme.c
+++ b/drivers/nvme/nvme.c
@@ -13,8 +13,6 @@
 #include <dm/device-internal.h>
 #include "nvme.h"
 
-struct nvme_info *nvme_info;
-
 #define NVME_Q_DEPTH		2
 #define NVME_AQ_DEPTH		2
 #define NVME_SQ_SIZE(depth)	(depth * sizeof(struct nvme_command))
@@ -650,7 +648,8 @@
 
 	memset(ns, 0, sizeof(*ns));
 	ns->dev = ndev;
-	ns->ns_id = desc->devnum - ndev->blk_dev_start + 1;
+	/* extract the namespace id from the block device name */
+	ns->ns_id = trailing_strtol(udev->name) + 1;
 	if (nvme_identify(ndev, ns->ns_id, 0, (dma_addr_t)id))
 		return -EIO;
 
@@ -762,8 +761,10 @@
 
 static int nvme_bind(struct udevice *udev)
 {
+	static int ndev_num;
 	char name[20];
-	sprintf(name, "nvme#%d", nvme_info->ndev_num++);
+
+	sprintf(name, "nvme#%d", ndev_num++);
 
 	return device_set_name(udev, name);
 }
@@ -815,8 +816,6 @@
 		goto free_queue;
 
 	nvme_get_info_from_identify(ndev);
-	ndev->blk_dev_start = nvme_info->ns_num;
-	list_add(&ndev->node, &nvme_info->dev_list);
 
 	return 0;