qed: Don't use attention PTT for configuring BW

Commit 653d2ffd6405 ("qed*: Fix link indication race") introduced another
race - one of the inner functions called from the link-change flow is
explicitly using the slowpath context dedicated PTT instead of gaining
that PTT from the caller. Since this flow can now be called from
a different context as well, we're in risk of the PTT breaking.

Fixes: 653d2ffd6405 ("qed*: Fix link indication race")
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>