staging: wfx: do not update uapsd if not necessary

wfx_conf_tx() is called for each queue. On every call, the function
updates UAPSD mask and PM mode for all queues. It is a pity since the
UAPSD configuration very rarely changes and it makes exchanges between
the host and the chip more difficult to track.

This patch avoid to update UAPSD and Power Mode in most usual cases.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200115135338.14374-43-Jerome.Pouiller@silabs.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>