spl: nvme: Make this depend on SPL_BLK

As this is an SPL related driver, and in SPL enabling SPL_BLK is
optional, make this depend on the correct symbol.

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index 6405374..80c80d9 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -1293,7 +1293,7 @@
 
 config SPL_NVME
 	bool "NVM Express device support"
-	depends on BLK
+	depends on SPL_BLK
 	select FS_LOADER
 	select SPL_BLK_FS
 	help