leds: qti-flash: Set TORCH_MODE for bharger-flash

In Bharger-flash, the charger h/w is to be notified
of the Torch-charger concurrency. This is done by setting
the TORCH_MODE bit before enabling the torch-config.
Implement this and identify bharger-flash based on
the peripheral-subtype.

Change-Id: I6207f45f506ab595bd261a297abdd8f40990c8d4
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>