configs: add PLATFORM_C to configs using ENTROPY_C

This is necessary to let entropy being able to gather entropy data from
the native platform source.

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/tests/scripts/components-configuration-crypto.sh b/tests/scripts/components-configuration-crypto.sh
index cb66e37..f5b3436 100644
--- a/tests/scripts/components-configuration-crypto.sh
+++ b/tests/scripts/components-configuration-crypto.sh
@@ -2204,6 +2204,7 @@
         #define MBEDTLS_AES_C
         #define MBEDTLS_CTR_DRBG_C
         #define MBEDTLS_ENTROPY_C
+        #define MBEDTLS_PLATFORM_C
         #define MBEDTLS_PSA_CRYPTO_C
         #define MBEDTLS_SELF_TEST
 END