taprio: do not use BIT() in TCA_TAPRIO_ATTR_FLAG_* definitions

BIT() macro definition is internal to the Linux kernel and is not
to be used in UAPI headers; replace its usage with the _BITUL() macro
that is already used elsewhere in the header.

Fixes: 9c66d156

 ("taprio: Add support for hardware offloading")
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Acked-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>