NVMe: do PCI enumerate before nvme scan

Make sure that the PCI busses are enumerated before trying to
find a NVMe device.
Signed-off-by: NPatrick Wildt <patrick@blueri.se>
Reviewed-by: NBin Meng <bmeng.cn@gmail.com>

include/config_distro_bootcmd.h

@@ -189,6 +189,7 @@
 		"fi\0" \
 	\
 	"nvme_boot=" \
+		BOOTENV_RUN_PCI_ENUM \
 		BOOTENV_RUN_NVME_INIT \
 		BOOTENV_SHARED_BLKDEV_BODY(nvme)
 #define BOOTENV_DEV_NVME	BOOTENV_DEV_BLKDEV