net: dsa: make current DSA core driver obsolete

Current DSA TX/RX way was hard-coded in ethernet devices driver
with ETH_DSA_SUPPORT and NET_DSA.
This patch is to make such way obsolete, as we actually will support
a better DSA framework to handle this in NET/DSA core driver.
To make legacy devices not affected, below options are used instead.

- ETH_DSA_SUPPORT_DEPRECATED
- NET_DSA_DEPRECATED

Once the legacy devices are converted to new DSA framework, this code
could be removed.

Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com>