Update references to old Github organisation

Replace references to ARMmbed organisation with the new
org, Mbed-TLS, following project migration.

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/include/psa/crypto_config.h b/include/psa/crypto_config.h
index e2446cb..8b6dba5 100644
--- a/include/psa/crypto_config.h
+++ b/include/psa/crypto_config.h
@@ -94,14 +94,14 @@
 #define PSA_WANT_ECC_MONTGOMERY_255             1
 /*
  * Curve448 is not yet supported via the PSA API in Mbed TLS
- * (https://github.com/ARMmbed/mbedtls/issues/4249). Thus, do not enable it by
+ * (https://github.com/Mbed-TLS/mbedtls/issues/4249). Thus, do not enable it by
  * default.
  */
 //#define PSA_WANT_ECC_MONTGOMERY_448             1
 #define PSA_WANT_ECC_SECP_K1_192                1
 /*
  * SECP224K1 is buggy via the PSA API in Mbed TLS
- * (https://github.com/ARMmbed/mbedtls/issues/3541). Thus, do not enable it by
+ * (https://github.com/Mbed-TLS/mbedtls/issues/3541). Thus, do not enable it by
  * default.
  */
 //#define PSA_WANT_ECC_SECP_K1_224                1