Newer ENA devices can write data to rx buffers with an offset
from the beginning of the buffer.

This commit adds support for this feature in the driver.
Signed-off-by: Sameeh Jubran <sameehj@amazon.com>
Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>