drm/msm/disp: set num_planes and fetch_mode in INTERLEAVED_RGB_FMT

drm/msm/disp: set num_planes and fetch_mode in INTERLEAVED_RGB_FMT

All interleaved RGB formats use only 1 plane and MDP_FETCH_LINEAR.
Specify num_planes and fetch_mode directly in the macro and remove
unused parameters.

Reviewed-by: Jessica Zhang <jessica.zhang@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/688163/
Link: https://lore.kernel.org/r/20251114-dpu-formats-v3-2-cae312379d49@oss.qualcomm.com
Tested-by: Luca Weiss <luca.weiss@fairphone.com> # qcm6490-fairphone-fp5
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>