ARM: dts: msm: Set the low SOC fifo length

For frequent fifo-update events at lower SOC (state of charge)
set the fifo-length to 2.

Change-Id: I805f1ddc98de61dfebf76684bb43193c1b5192cd
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>