drm/msm/dsi: dsi_cfg: Merge SC7180 config into SDM845

drm/msm/dsi: dsi_cfg: Merge SC7180 config into SDM845

The configs are identical, other than the number of *maximum* DSI
hosts allowed. This isn't an issue, unless somebody deliberately
tries to access the inexistent host by adding a dt node for it.

Remove the SC7180 struct and point the hw revision match to the
SDM845's one. On a note, this could have been done back when
7180 support was introduced.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/527654/
Link: https://lore.kernel.org/r/20230307-topic-dsi_qcm-v6-5-70e13b1214fa@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>