nrf_security: Disabling OBERON_BACKEND being auto-selected

-Disabling unnecessary auto-select of OBERON_BACKEND for all
 non TF-M builds using legacy APIs
-Enabling removal of prompt for OBERON_BACKEND in case CC3XX_BACKEND
 is enabled

ref: NCSDK-13773
ref: NCSDK-13762

Signed-off-by: Frank Audun Kvamtrø <[email protected]>

Author: frkv

nrf_security/Kconfig

@@ -21,7 +21,7 @@ config NORDIC_SECURITY_BACKEND
 	depends on SOC_FAMILY_NRF
 	select NRF_SECURITY
 	select MBEDTLS_LEGACY_CRYPTO_C
-	select OBERON_BACKEND
+	select OBERON_BACKEND if BUILD_WITH_TFM
 	select DISABLE_MBEDTLS_BUILTIN if MBEDTLS
 	help
 	  Using this configuration enables legacy support for mbed TLS APIs

nrf_security/Kconfig.legacy

@@ -301,8 +301,7 @@ config OBERON_BACKEND
 	bool
 	prompt "Configuration to enable nrf_oberon for legacy mbed TLS APIs"
 	select NRF_OBERON
-	depends on !CC3XX_BACKEND_FORCED
-		#  && !CC3XX_BACKEND - Can't add filter because of CI
+	depends on !(CC3XX_BACKEND_FORCED || CC3XX_BACKEND)
 	help
 	  This configuration enables legacy mbed TLS APIs using nrf_oberon.
 	  PSA_CRYPTO_DRIVER_OBERON should be used instead and will replace this once