sim: Remove curve specific ECDSA TLVs

Remove those TLVs that are tied to a specific curve and modify the
code to use the new generic ECDSA TLV.

Signed-off-by: Roland Mikhel <roland.mikhel@arm.com>
Change-Id: Iffe9052580c99e75118cf5df4286e0e9a2af4a8c
diff --git a/sim/src/image.rs b/sim/src/image.rs
index d484dc0..424f646 100644
--- a/sim/src/image.rs
+++ b/sim/src/image.rs
@@ -1889,10 +1889,7 @@
             TlvGen::new_rsa3072_pss()
         } else if Caps::EcdsaP256.present() {
             TlvGen::new_ecdsa()
-        } else if Caps::EcdsaSig.present() {
-            TlvGen::new_generic_ecdsa()
-        }
-         else if Caps::Ed25519.present() {
+        } else if Caps::Ed25519.present() {
             TlvGen::new_ed25519()
         } else {
             TlvGen::new_hash_only()