drm/msm/dpu: drop dpu_hw_dsc_destroy() prototype

drm/msm/dpu: drop dpu_hw_dsc_destroy() prototype

[ Upstream commit d9792823d18ff9895eaf5769a29a54804f24bc25 ]

The commit a106ed98af68 ("drm/msm/dpu: use devres-managed allocation for
HW blocks") dropped all dpu_hw_foo_destroy() functions, but the
prototype for dpu_hw_dsc_destroy() was omitted. Drop it now to clean up
the header.

Fixes: a106ed98af68 ("drm/msm/dpu: use devres-managed allocation for HW blocks")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Jessica Zhang <jesszhan0024@gmail.com>
Patchwork: https://patchwork.freedesktop.org/patch/683697/
Link: https://lore.kernel.org/r/20251027-dpu-drop-dsc-destroy-v1-1-968128de4bf6@oss.qualcomm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>