ARM: dts: msm: add SmartDMA 2.5 support to SDE for sdm855

Update the sdm855 SDE device tree node to set the
correct smart DMA version supported by this chip.

Change-Id: I6e431d9e8171b33e9c6fea7f31144fb23f455d14
Signed-off-by: Steve Cohen <cohens@codeaurora.org>