nrf_security: Fix MBEDTLS_CFG_FILE Kconfig symbol

Removes a prompt, type and duplicated help text from this symbol
as this is an override symbol only

Signed-off-by: Jamie McCrae <[email protected]>

Author: nordicjm

subsys/nrf_security/Kconfig

@@ -64,11 +64,7 @@ config MBEDTLS_PSA_CRYPTO_BUILTIN_KEYS
 	  Promptless option used to control if the PSA Crypto core should have support for builtin keys or not.
 
 config MBEDTLS_CFG_FILE
-	string "mbed TLS configuration file"
 	default "nrf-config.h"
-	help
-	  Name of the config file for mbed TLS. This configuration file is used
-	  in configurations with or without PSA APIs supported.
 
 config MBEDTLS_PSA_CRYPTO_CONFIG
 	bool