coresight-tpdm: Fix for re-programming TPDM

Fix to disable MCMB TPDM. On reprogramming the TPDM
we do not clear the old configuration for lane enable and
lane trigger.

Change-Id: I3606f0f2c372e29c27db89e2c0363785939c0842
Signed-off-by: Satyajit Desai <sadesai@codeaurora.org>