bootutil: PSA Crypto ECDSA enablement

This commit enables ECDSA signature verification using
PSA Crypto API.

Signed-off-by: Roland Mikhel <roland.mikhel@arm.com>
Change-Id: I51c7aadba03348f335e89d9252e70c09f8787f30
diff --git a/boot/bootutil/src/caps.c b/boot/bootutil/src/caps.c
index 49bdfec..d7cd590 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_EC384)
+    res |= BOOTUTIL_CAP_ECDSA_P384;
+#endif
 #if defined(MCUBOOT_SIGN_ED25519)
     res |= BOOTUTIL_CAP_ED25519;
 #endif