ARM: dts: msm: Update stream ids for graphics smmu

The context bank 0 takes stream ids 0 and 1 for
plutonium, and context bank 1 takes stream id 2.
Update the device tree to reflect this change.

Change-Id: Icb2a50ea3433c49deffb355288c2e7d5f5259a27
Signed-off-by: Neeti Desai <neetid@codeaurora.org>