pk: guard mbedtls_pk_setup_opaque() with CRYPTO_CLIENT instead of USE_PSA

This commit also solves related issues in order to have test
components related to CRYPTO_CLIENT passing.

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/library/pk.c b/library/pk.c
index 076d3a8..e7a2af4 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -151,7 +151,7 @@
     return 0;
 }
 
-#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#if defined(MBEDTLS_PSA_CRYPTO_CLIENT)
 /*
  * Initialise a PSA-wrapping context
  */
@@ -188,7 +188,7 @@
 
     return 0;
 }
-#endif /* MBEDTLS_USE_PSA_CRYPTO */
+#endif /* MBEDTLS_PSA_CRYPTO_CLIENT */
 
 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
 /*