ARM: dts: msm: modify interrupt flag for wled device on PMI8994

The wled driver is not statically handling interrupt flags.
Pass proper flag such as IRQ_TYPE_EDGE_RISING for wled
"sc-irq" interrupt through device node.

Change-Id: I90974bd7995949a97bb7070e86c469cde646096a
Signed-off-by: Tirupathi Reddy <tirupath@codeaurora.org>