Fix dependency on low-level hash modules

None of the TLS code is calling low-level hash functions directly. So
the correct dependencies here are MD_CAN.

(I checked and this was the only occurrence.)

Signed-off-by: Manuel Pégourié-Gonnard <manuel.pegourie-gonnard@arm.com>
diff --git a/include/mbedtls/check_config.h b/include/mbedtls/check_config.h
index 7852859..8c8130b 100644
--- a/include/mbedtls/check_config.h
+++ b/include/mbedtls/check_config.h
@@ -461,11 +461,11 @@
 #endif
 
 #if defined(MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED) &&        \
-    !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) &&              \
-    ( !defined(MBEDTLS_SHA256_C) &&                             \
-      !defined(MBEDTLS_SHA512_C) &&                             \
-      !defined(MBEDTLS_SHA1_C) )
-#error "!MBEDTLS_SSL_KEEP_PEER_CERTIFICATE requires MBEDTLS_SHA512_C, MBEDTLS_SHA256_C or MBEDTLS_SHA1_C"
+    !defined(MBEDTLS_SSL_KEEP_PEER_CERTIFICATE) &&            \
+    !defined(MBEDTLS_MD_CAN_SHA256) &&                        \
+    !defined(MBEDTLS_MD_CAN_SHA512) &&                        \
+    !defined(MBEDTLS_MD_CAN_SHA1)
+#error "!MBEDTLS_SSL_KEEP_PEER_CERTIFICATE requires SHA-512, SHA-256 or SHA-1".
 #endif
 
 #if defined(MBEDTLS_MD_C) && \