drm/msm/dsi: don't dump registers past the mapped region

In the Linux kernel, the following vulnerability has been resolved: drm/msm/dsi: don't dump registers past the mapped region On DSI 6G platforms the IO address space is internally adjusted by io_offset. Later this adjusted address might be used for memory dumping. However the size that is used for memory dumping isn't adjusted to account for the io_offset, leading to the potential access to the unmapped region. Lower ctrl_size by the io_offset value to prevent access past the mapped area. msm_disp_snapshot_add_block+0x1d4/0x3c8 [msm] (P) msm_dsi_host_snapshot+0x4c/0x78 [msm] msm_dsi_snapshot+0x28/0x50 [msm] msm_disp_snapshot_capture_state+0x74/0x140 [msm] msm_disp_snapshot_state_sync+0x60/0x90 [msm] _msm_disp_snapshot_work+0x30/0x90 [msm] kthread_worker_fn+0xdc/0x460 kthread+0x120/0x140 Patchwork: https://patchwork.freedesktop.org/patch/721747/