wl12xx: fix erroneous commit (cb5ae0)

Due to rebase error, the patch for commit cb5ae0 ("wl12xx: configure
rates when working in ibss mode") was wrong - a blob was added
into the wrong function. fix it.

Signed-off-by: Eliad Peller <eliad@wizery.com>
Signed-off-by: Luciano Coelho <coelho@ti.com>