ARM: dts: msm: Change QDSS pipe index to 3 for SDM660

Currently same pipe index is used for both QDSS and DPL pipes for SDM660.
This causes QDSS not working in composition 90DB having both QDSS and DPL
interfaces. Hence fix it by changing QDSS pipe index to 3 so that both
QDSS and DPL works fine with 90DB composition on SDM660.

Change-Id: I7c799716cff7321985fcb88a8073737343a932f5
Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>