[nrf noup] net: tests: Add legacy crypto API support for big_http_download

-We handle legacy Crypto API support specially (favoring PSA crypto)
 the tests here require MD interface to build, which needs the config
 MBEDTLS_LEGACY_CRYPTO_C to be enable to get access to

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

Author: frkv

samples/net/sockets/big_http_download/prj.conf

@@ -3,6 +3,7 @@ CONFIG_REQUIRES_FULL_LIBC=y
 CONFIG_MBEDTLS=y
 CONFIG_MBEDTLS_ENABLE_HEAP=y
 CONFIG_MBEDTLS_MD=y
+CONFIG_MBEDTLS_LEGACY_CRYPTO_C=y
 CONFIG_MAIN_STACK_SIZE=2536
 
 # Networking config