bootm: Use selected configuration for ramdisk and fdt

If a specific configuraion is selected by the bootm command, e.g. with
'bootm 84000000#recoveryconf' we must honour this for not just the kernel,
but also the ramdisk and FDT.

In the conversion to using a common fit_image_load() function for loading
images from FITs (commits a51ec63 and 53f375f) this feature was lost.
Reinstate it by passing the selected configuration back from
fit_image_load() to boot_get_kernel(), then use this configuration
(which is stored in images->fit_uname_cfg) in both boot_get_ramdisk()
and boot_get_fdt().

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/common/image.c b/common/image.c
index 1be384f..327006e 100644
--- a/common/image.c
+++ b/common/image.c
@@ -811,7 +811,7 @@
 	char *end;
 #endif
 #if defined(CONFIG_FIT)
-	const char	*fit_uname_config = NULL;
+	const char	*fit_uname_config = images->fit_uname_cfg;
 	const char	*fit_uname_ramdisk = NULL;
 	ulong		default_addr;
 	int		rd_noffset;
@@ -907,7 +907,7 @@
 		case IMAGE_FORMAT_FIT:
 			rd_noffset = fit_image_load(images, FIT_RAMDISK_PROP,
 					rd_addr, &fit_uname_ramdisk,
-					fit_uname_config, arch,
+					&fit_uname_config, arch,
 					IH_TYPE_RAMDISK,
 					BOOTSTAGE_ID_FIT_RD_START,
 					FIT_LOAD_REQUIRED, &rd_data, &rd_len);