staging: wfx: drop argument tx_allowed_mask since it is constant now

Following the remove of asleep_mask, the tx_allowed_mask argument passed
to various functions is now always the same. Drop this argument and
simplify the code.

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200401110405.80282-14-Jerome.Pouiller@silabs.com


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