arm: mvebu: turris_omnia: Add NVMe to boot targets

U-Boot for Turris Omnia has already enabled NVMe support. So add NVMe to
boot targets.

Signed-off-by: Pali Rohár <pali@kernel.org>
diff --git a/include/configs/turris_omnia.h b/include/configs/turris_omnia.h
index f2fc374..8119340 100644
--- a/include/configs/turris_omnia.h
+++ b/include/configs/turris_omnia.h
@@ -54,6 +54,7 @@
 
 #define BOOT_TARGET_DEVICES(func) \
 	func(MMC, mmc, 0) \
+	func(NVME, nvme, 0) \
 	func(SCSI, scsi, 0) \
 	func(USB, usb, 0) \
 	func(PXE, pxe, na) \