rsa: add a structure for the padding

The rsa signature use a padding algorithm. By default, we use the
padding pkcs-1.5. In order to add some new padding algorithm, we
add a padding framework to manage several padding algorithm.
The choice of the padding is done in the file .its.

Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/common/image-fit.c b/common/image-fit.c
index 8d39a24..ac901e1 100644
--- a/common/image-fit.c
+++ b/common/image-fit.c
@@ -165,6 +165,7 @@
 	uint8_t *value;
 	int value_len;
 	char *algo;
+	const char *padding;
 	int required;
 	int ret, i;
 
@@ -184,6 +185,10 @@
 		printf(" (required)");
 	printf("\n");
 
+	padding = fdt_getprop(fit, noffset, "padding", NULL);
+	if (padding)
+		printf("%s  %s padding: %s\n", p, type, padding);
+
 	ret = fit_image_hash_get_value(fit, noffset, &value,
 				       &value_len);
 	printf("%s  %s value:   ", p, type);