Move i.MX8 container image loading support to common/spl

To facilitate testing loading i.MX8 container images, move the
parse-container code to common/spl.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
diff --git a/common/spl/Kconfig b/common/spl/Kconfig
index 4632359..ad574a6 100644
--- a/common/spl/Kconfig
+++ b/common/spl/Kconfig
@@ -330,6 +330,20 @@
 	  If disabled, Legacy images are booted if the image magic and size
 	  are correct, without further integrity checks.
 
+config SPL_LOAD_IMX_CONTAINER
+	bool "Enable SPL loading and booting of i.MX8 Containers"
+	depends on SPL
+	help
+	  Support booting U-Boot from an i.MX8 container image. If you are not
+	  using i.MX8, say 'n'.
+
+config IMX_CONTAINER_CFG
+	string "i.MX8 Container config file"
+	depends on SPL && SPL_LOAD_IMX_CONTAINER
+	help
+	  Specify the cfg file for generating the container image which will be
+	  loaded by SPL.
+
 config SPL_SYS_MALLOC_SIMPLE
 	bool "Only use malloc_simple functions in the SPL"
 	help