nrf_security: stop forcing CONFIG_MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG to y

This reverts what 60ab340 did.

With the appropriate adaptations the Kconfig option should now
always be the chosen option by default when using nrf_security.

Signed-off-by: Tomi Fontanilles <tomi.fontanilles@nordicsemi.no>

Author: tomi-font

subsys/nrf_security/CMakeLists.txt

@@ -88,8 +88,6 @@ else()
   nrf_security_debug("Building for pure Zephyr")
 endif()
 
-set(CONFIG_MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG  True)
-
 # Add library for crypto configs (NS/S-only build)
 # The name and intent of this comes from TF-M distribution
 add_library(psa_crypto_config INTERFACE)

subsys/nrf_security/tfm/CMakeLists.txt

@@ -77,9 +77,6 @@ set(CONFIG_BUILD_WITH_TFM                           False)
 # Enable the MBEDTLS_ENABLE_HEAP configuration since TF-M implements heap in crypto_init.c
 set(CONFIG_MBEDTLS_ENABLE_HEAP                      True)
 
-# Ensure that RNG is not usling legacy code
-set(CONFIG_MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG          True)
-
 # Ensure that PSA core is built inside TF-M image
 set(CONFIG_MBEDTLS_PSA_CRYPTO_C                     True)