drm/msm/disp/dpu: Remove unused functions from dpu_formats.c

Remove dpu_format_get_block_size, dpu_format_get_framebuffer_size,
dpu_set_scaler_v2 and dpu_copy_formats they are unused and unneeded.

Signed-off-by: Jordan Crouse <jcrouse@codeauorora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>