sim: Add generic ECDSA TLV support

Add support to the simulator so that
the generic ECDSA TLV can be tested.

Signed-off-by: Roland Mikhel <roland.mikhel@arm.com>
Change-Id: I3322ed829d150ff35abfaaa8ecf69ab7017bd7cf
diff --git a/sim/src/image.rs b/sim/src/image.rs
index 424f646..d484dc0 100644
--- a/sim/src/image.rs
+++ b/sim/src/image.rs
@@ -1889,7 +1889,10 @@
             TlvGen::new_rsa3072_pss()
         } else if Caps::EcdsaP256.present() {
             TlvGen::new_ecdsa()
-        } else if Caps::Ed25519.present() {
+        } else if Caps::EcdsaSig.present() {
+            TlvGen::new_generic_ecdsa()
+        }
+         else if Caps::Ed25519.present() {
             TlvGen::new_ed25519()
         } else {
             TlvGen::new_hash_only()