leds: qpnp-flash-v2: Disable the safety timer by default

Safety timer is enabled in the HW by default. Make it disabled
by default and enable based on the client's need.

Change-Id: I7967b91deeed5f87557e59f1dd16ce41a22ae134
Signed-off-by: Kiran Gunda <kgunda@codeaurora.org>