Update baremetal config to exclude MBEDTLS_SHAxxx_USE_A64_CRYPTO_IF_PRESENT

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/scripts/config.py b/scripts/config.py
index 17fbe65..1a71cb3 100755
--- a/scripts/config.py
+++ b/scripts/config.py
@@ -278,6 +278,8 @@
     'MBEDTLS_THREADING_C', # requires a threading interface
     'MBEDTLS_THREADING_PTHREAD', # requires pthread
     'MBEDTLS_TIMING_C', # requires a clock
+    'MBEDTLS_SHA256_USE_A64_CRYPTO_IF_PRESENT', # requires an OS for runtime-detection
+    'MBEDTLS_SHA512_USE_A64_CRYPTO_IF_PRESENT', # requires an OS for runtime-detection
 ])
 
 def keep_in_baremetal(name):