Add simulator support for RSA-3072 sigs

Signed-off-by: Fabio Utzig <utzig@apache.org>
diff --git a/sim/src/caps.rs b/sim/src/caps.rs
index 2751618..f316fd6 100644
--- a/sim/src/caps.rs
+++ b/sim/src/caps.rs
@@ -12,6 +12,7 @@
     EncRsa               = (1 << 5),
     EncKw                = (1 << 6),
     ValidatePrimarySlot  = (1 << 7),
+    RSA3072              = (1 << 8),
 }
 
 impl Caps {