Replace `MBEDTLS_MD_CAN_SHA512` with `PSA_WANT_ALG_SHA_512`

Signed-off-by: Gabor Mezei <gabor.mezei@arm.com>
diff --git a/tf-psa-crypto/drivers/builtin/src/md.c b/tf-psa-crypto/drivers/builtin/src/md.c
index cd3f7f2..97caf66 100644
--- a/tf-psa-crypto/drivers/builtin/src/md.c
+++ b/tf-psa-crypto/drivers/builtin/src/md.c
@@ -106,7 +106,7 @@
 };
 #endif
 
-#if defined(MBEDTLS_MD_CAN_SHA512)
+#if defined(PSA_WANT_ALG_SHA_512)
 static const mbedtls_md_info_t mbedtls_sha512_info = {
     MD_INFO(MBEDTLS_MD_SHA512, 64, 128)
 };
@@ -163,7 +163,7 @@
         case MBEDTLS_MD_SHA384:
             return &mbedtls_sha384_info;
 #endif
-#if defined(MBEDTLS_MD_CAN_SHA512)
+#if defined(PSA_WANT_ALG_SHA_512)
         case MBEDTLS_MD_SHA512:
             return &mbedtls_sha512_info;
 #endif
@@ -781,7 +781,7 @@
  */
 static const int supported_digests[] = {
 
-#if defined(MBEDTLS_MD_CAN_SHA512)
+#if defined(PSA_WANT_ALG_SHA_512)
     MBEDTLS_MD_SHA512,
 #endif
 
@@ -857,7 +857,7 @@
 #if defined(PSA_WANT_ALG_SHA_384)
     { "SHA384", MBEDTLS_MD_SHA384 },
 #endif
-#if defined(MBEDTLS_MD_CAN_SHA512)
+#if defined(PSA_WANT_ALG_SHA_512)
     { "SHA512", MBEDTLS_MD_SHA512 },
 #endif
 #if defined(PSA_WANT_ALG_SHA3_224)