leds: qpnp-flash-v2: Add support for dynamic torch current update

Add support to update torch current for all torch devices under
a switch if switch has already been enabled, without requiring
disablement of switch before updating new value.

Change-Id: I51e8d5701395fa095e3623cba0d2aaeae7c910ef
Signed-off-by: Jishnu Prakash <jprakash@codeaurora.org>