Fixed memory leak in emac_esp_new_dma function.
Polished ESP EMAC cache management.
Added emac_periph definitions based on SoC features and improved(generalized) ESP EMAC GPIO
initialization.
Added ESP EMAC GPIO reservation.
Added check for frame error condition indicated by EMAC DMA and created a target test.
The interface name can be used in socket API, i.e. setsockopt(). The API esp_netif_get_netif_impl_name() shoudl be used to populate standard
interface structure struct ifreq.