ARM: msm: dts: Update pdc compatible flag for sdm845 v2 version

PDC pin mapping are different for v1 and v2 sdm845 devices. Update the
compatible flag for v2 device such that correct mapping is used.

Change-Id: Ie4f8e3d83a7f5f2d05a739be7c7879ce82fd8c1e
Signed-off-by: Archana Sathyakumar <asathyak@codeaurora.org>