eea: introduce ring and descriptor structures

eea: introduce ring and descriptor structures

Add basic driver framework for the Alibaba Elastic Ethernet Adapter(EEA).

This commit introduces the ring and descriptor implementations.

These structures and ring APIs are used by the RX, TX, and admin queues.

Reviewed-by: Dust Li <dust.li@linux.alibaba.com>
Reviewed-by: Philo Lu <lulie@linux.alibaba.com>
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Link: https://patch.msgid.link/20260514095138.80680-3-xuanzhuo@linux.alibaba.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>