drivers/crypto: aspeed: Add Caliptra ECDSA384 support

Aspeed AST27xx SoCs integrate the CPTRA 1.0 secure IP, which export
an ECDSA384_SIGNATURE_VERIFY mailbox command service for SoC to use.

This patch is verified by the FIT signature verification using the
"sha384,ecdsa384" algorithm.

Signed-off-by: Chia-Wei Wang <chiawei_wang@aspeedtech.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/crypto/aspeed/Kconfig b/drivers/crypto/aspeed/Kconfig
index 473e3e5..6efcd7d 100644
--- a/drivers/crypto/aspeed/Kconfig
+++ b/drivers/crypto/aspeed/Kconfig
@@ -28,3 +28,13 @@
 
 	  Enabling this allows the use of SHA operations in hardware. Note that only
 	  SHA384 and SHA512 are supported by Caliptra 1.0.
+
+config ASPEED_CPTRA_ECDSA
+	bool "Caliptra ECDSA384 signature verifier for Aspeed SoCs"
+	depends on ECDSA_VERIFY || SPL_ECDSA_VERIFY
+	help
+	  Select this option to enable a driver for using the ECDSA384_SIGNATURE_VERIFY
+	  feature of Caliptra, which is integrated in AST27xx BMC SoCs.
+
+	  Enabling this allows the use of ECDSA384 signature verification in hardware.
+	  Note that only ECDSA384 is supported by Caliptra.