config_psa: include legacy module adjusting in MCUBOOT

MCUboot has its own version of the PSA Crypto core, named
"thin_psa_crypto_core.c" which is included in MCUboot's
build process when the MCUBOOT_USE_PSA_CRYPTO build symbol is
set. MCUBOOT_USE_PSA_CRYPTO mimics what MBEDTLS_PSA_CRYPTO_C
does for the official Mbed TLS, so we need to replicate
this symbol in "config_psa.h" in order to get the proper
PSA builtin support.

Signed-off-by: Valerio Setti <vsetti@baylibre.com>
(cherry picked from commit b9b26b7)
Signed-off-by: Tomi Fontanilles <tomi.fontanilles@nordicsemi.no>

Author: valeriosetti

include/mbedtls/config_psa.h

@@ -34,7 +34,7 @@
  * before we deduce what built-ins are required. */
 #include "psa/crypto_adjust_config_key_pair_types.h"
 
-#if defined(MBEDTLS_PSA_CRYPTO_C)
+#if defined(MBEDTLS_PSA_CRYPTO_C) || defined(MCUBOOT_USE_PSA_CRYPTO)
 /* If we are implementing PSA crypto ourselves, then we want to enable the
  * required built-ins. Otherwise, PSA features will be provided by the server. */
 #include "mbedtls/config_adjust_legacy_from_psa.h"