spl: Convert net to spl_load

This converts the net load method to use spl_load. As a result, it also
adds support for LOAD_FIT_FULL and IMX images.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/test/image/spl_load_net.c b/test/image/spl_load_net.c
index f570cef..9d067a7 100644
--- a/test/image/spl_load_net.c
+++ b/test/image/spl_load_net.c
@@ -248,5 +248,7 @@
 	return ret;
 }
 SPL_IMG_TEST(spl_test_net, LEGACY, DM_FLAGS);
+SPL_IMG_TEST(spl_test_net, LEGACY_LZMA, DM_FLAGS);
+SPL_IMG_TEST(spl_test_net, IMX8, DM_FLAGS);
 SPL_IMG_TEST(spl_test_net, FIT_INTERNAL, DM_FLAGS);
 SPL_IMG_TEST(spl_test_net, FIT_EXTERNAL, DM_FLAGS);