Updates for review part 2

Ethernet changes
- MDC, MDIO tidy up
- IPV6 local address not allocated on ethernet adapters

Add P4 to builds
Other fixes as per review

Author: AdrianSoundy

targets/ESP32/_IDF/esp32/partitions_nanoclr_2mb.csv

@@ -8,7 +8,7 @@ nvs,      data, nvs,     0x9000,   0x6000,
 phy_init, data, phy,     0xf000,   0x1000,
 # Factory area for nanoCLR - 1728k
 factory,  app, factory,  0x10000,  0x1B0000,
-# Deployment area for Managed code 12k
+# Deployment area for Managed code 192k
 deploy,   data, 0x84,    0x1C0000, 0x30000,
 # Config data for Network, Wireless, certificates, user data  64k
 config,   data, littlefs,  0x1F0000, 0x10000,