Add ed25519 verification to sim

Signed-off-by: Fabio Utzig <utzig@apache.org>
diff --git a/boot/bootutil/include/bootutil/caps.h b/boot/bootutil/include/bootutil/caps.h
index b38bc4f..1958348 100644
--- a/boot/bootutil/include/bootutil/caps.h
+++ b/boot/bootutil/include/bootutil/caps.h
@@ -41,6 +41,7 @@
 #define BOOTUTIL_CAP_ENC_KW                 (1<<6)
 #define BOOTUTIL_CAP_VALIDATE_PRIMARY_SLOT  (1<<7)
 #define BOOTUTIL_CAP_RSA3072                (1<<8)
+#define BOOTUTIL_CAP_ED25519                (1<<9)
 
 /*
  * Query the number of images this bootloader is configured for.  This
diff --git a/boot/bootutil/src/caps.c b/boot/bootutil/src/caps.c
index f2126d7..96f27b3 100644
--- a/boot/bootutil/src/caps.c
+++ b/boot/bootutil/src/caps.c
@@ -35,6 +35,9 @@
 #if defined(MCUBOOT_SIGN_EC256)
     res |= BOOTUTIL_CAP_ECDSA_P256;
 #endif
+#if defined(MCUBOOT_SIGN_ED25519)
+    res |= BOOTUTIL_CAP_ED25519;
+#endif
 #if defined(MCUBOOT_OVERWRITE_ONLY)
     res |= BOOTUTIL_CAP_OVERWRITE_UPGRADE;
 #else