staging: wfx: place hif_tx_mib functions into a .c file

Until now, all functions from hif_tx_mib.h are declared "static inline".
However, they are not time critical. So, it does not make so much sense.

We prefer to place them in a .c file as for other hif functions.

Signed-off-by: Jérôme Pouiller <jerome.pouiller@silabs.com>
Link: https://lore.kernel.org/r/20200406111756.154086-9-Jerome.Pouiller@silabs.com


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