RDMA/efa: Add data polling capability feature bit

Add feature bit to existing device caps field. EFA supports data polling
of 128 bytes blocks.

The flag indicates that the NIC guarentees that a 128 byte aligned block
is written in order, ie that observing the last 8 bits of the block mean
the prior 127 bytes are also written.

It is useful for "last data polling" acceleration techniques.

Link: https://lore.kernel.org/r/20230219081328.10419-1-mrgolin@amazon.com


Reviewed-by: Yehuda Yitschak <yehuday@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Yonatan Nachum <ynachum@amazon.com>
Signed-off-by: Michael Margolin <mrgolin@amazon.com>
Acked-by: Gal Pressman <gal.pressman@linux.dev>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>