drm/msm/dpu: Rename `ctx` parameter to `intf` to match other functions

drm/msm/dpu: Rename `ctx` parameter to `intf` to match other functions

All other functions in dpu_hw_intf name the "self" parameter `intf`,
except dpu_hw_intf_setup_timing_engine() and the recently added
dpu_hw_intf_program_intf_cmd_cfg().  Clean that up for consistency.

Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/589903/
Link: https://lore.kernel.org/r/20240417-drm-msm-initial-dualpipe-dsc-fixes-v1-7-78ae3ee9a697@somainline.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>