input: touchboost: I misinterpretaded the panic log

..when a BT device was disconnected and what was actually causing
the crash was destroying the WQ.
Also fix a small bug where if the user underclocked below
input_boost_freq after a touch input max/min freqs
would be changed to wrong frequencies.

Change-Id: I93845c89eb731f215c5019554cfb5be782e22d79
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>