drm/msm/dpu: Remove arbitrary limit of 1 interface in DSC topology

drm/msm/dpu: Remove arbitrary limit of 1 interface in DSC topology

When DSC is enabled the number of interfaces is forced to be 1, and
documented that it is a "power-optimal" layout to use two DSC encoders
together with two Layer Mixers.  However, the same layout (two DSC
hard-slice encoders with two LMs) is also used when the display is
fed with data over two instead of one interface (common on 4k@120Hz
smartphone panels with Dual-DSI).  Solve this by simply removing the
num_intf = 1 assignment as the count is already calculated by computing
the number of physical encoders within the virtual encoder.

Fixes: 7e9cc175b159 ("drm/msm/disp/dpu1: Add support for DSC in topology")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Patchwork: https://patchwork.freedesktop.org/patch/637649/
Link: https://lore.kernel.org/r/20250217-drm-msm-initial-dualpipe-dsc-fixes-v3-3-913100d6103f@somainline.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>