Add support for ethernet-only configuration with Nanostack.

This saves about 100kB of flash when using ethernet only configuration.
Otherwise only border router configuration was supporting ethernet.

Author: Seppo Takalo

features/nanostack/FEATURE_ETHERNET_HOST/TOOLCHAIN_ARM/TARGET_LIKE_CORTEX_M0/libnanostack_armcc_Cortex-M0_ethernet_host.ar

@@ -350,7 +350,7 @@ class Config(object):
     __allowed_features = [
         "UVISOR", "BLE", "CLIENT", "IPV4", "LWIP", "COMMON_PAL", "STORAGE", "NANOSTACK",
         # Nanostack configurations
-        "LOWPAN_BORDER_ROUTER", "LOWPAN_HOST", "LOWPAN_ROUTER", "NANOSTACK_FULL", "THREAD_BORDER_ROUTER", "THREAD_END_DEVICE", "THREAD_ROUTER"
+        "LOWPAN_BORDER_ROUTER", "LOWPAN_HOST", "LOWPAN_ROUTER", "NANOSTACK_FULL", "THREAD_BORDER_ROUTER", "THREAD_END_DEVICE", "THREAD_ROUTER", "ETHERNET_HOST"
         ]
 
     def __init__(self, tgt, top_level_dirs=None, app_config=None):