Revert "drm/msm/dpu: support plane splitting in quad-pipe case"

Revert "drm/msm/dpu: support plane splitting in quad-pipe case"

This reverts commit 5978864e34b66bdae4d7613834c03dd5d0a0c891.

At least on Hamoa based devices, there are IOMMU faults:

arm-smmu 15000000.iommu: Unhandled context fault: fsr=0x402, iova=0x00000000, fsynr=0x3d0023, cbfrsynra=0x1c00, cb=13
arm-smmu 15000000.iommu: FSR    = 00000402 [Format=2 TF], SID=0x1c00
arm-smmu 15000000.iommu: FSYNR0 = 003d0023 [S1CBNDX=61 PNU PLVL=3]

While on some of these devices, there are also all sorts of artifacts on eDP.

Reverting this fixes these issues.

Closes: https://lore.kernel.org/r/z75wnahrp7lrl5yhfdysr3np3qrs6xti2i4otkng4ex3blfgrx@xyiucge3xykb/
Signed-off-by: Abel Vesa <abel.vesa@oss.qualcomm.com>
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Fixes: 5978864e34b6 ("drm/msm/dpu: support plane splitting in quad-pipe case")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/695549/
Link: https://lore.kernel.org/r/20251219-drm-msm-dpu-revert-quad-pipe-broken-v1-1-654b46505f84@oss.qualcomm.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>