RDMA/rxe: Fixes mr access supported list

RDMA/rxe: Fixes mr access supported list

A recent patch incorrectly did not include IB_ACCESS_RELAXED_ORDERING in
the list of supported access flags for the rxe driver. The driver actually
does nothing related to relaxed ordering but it causes no problems to
include it as supported but with no effect. This change caused ib_send_bw
and friends to not run correctly.

The correct approach is for the driver to allow any of the optional access
flags and otherwise ignore them. This patch adds IB_ACCESS_OPTIONAL to the
list of rxe supported flags.

Fixes: 02ed253770fb ("RDMA/rxe: Introduce rxe access supported flags")
Link: https://lore.kernel.org/r/20230613171654.19334-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>