habanalabs: allow user to modify TPC clock relaxation value

This patch allows the user to modify the TPC PLL clock relaxation value
on-the-fly in order to reduce power consumption.

To enable this, the patch removes the protection from the specific
register that controls this behavior.

Signed-off-by: Dalit Ben Zoor <dbenzoor@habana.ai>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>