The fact that the LSB in the register is the enable bit should not be an
implicit assumption between the driver and the device, properly document
that in the register definition.

Link: https://lore.kernel.org/r/20200225114010.21790-3-galpress@amazon.comReviewed-by: Firas JahJah <firasj@amazon.com>
Reviewed-by: Yossi Leybovich <sleybo@amazon.com>
Signed-off-by: Gal Pressman <galpress@amazon.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>