staging: fsl-mc/dpio: Fix early writing of valid bit

Commands written to the QMan software portals have a valid
bit in the "verb" field of the command that, when set with
the right value, notifies the hardware that the command is
fully written and ready to be processed.

The "verb" field should be the last one to be written in the
swp command registers, after all other fields are filled in.
The current implementation doesn't follow this rule for all
commands, which may result in an incompletely configured
command being processed by the hardware. Enforce the correct
order of writes to avoid this situation.

Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>