disp: msm: sde: add check for unsupported writeback output formats

Chroma sample types H1V2 and H2V1 are not supported in write back output.
Made changes to add atomic check for such unsupported output formats in
writeback.

Change-Id: Ic37865e0b0c64016df728cc753ad66c3b9e9d138
Signed-off-by: Andhavarapu Karthik <kartkart@codeaurora.org>