drm/amd/display: fix cursor offset on rotation 180

Cursor gets clipped off in the middle of the screen with hw rotation
180. Fix a miscalculation of cursor offset when it's placed near the
edges in the pipe split case.

Cursor bugs with hw rotation were reported on AMD issue tracker:
https://gitlab.freedesktop.org/drm/amd/-/issues/2247

The issues on rotation 270 was fixed by:
https://lore.kernel.org/amd-gfx/[email protected]/
that partially addressed the rotation 180 too. So, this patch is the
final bits for rotation 180.

Reported-by: Xaver Hugl <[email protected]>
Reviewed-by: Harry Wentland <[email protected]>
Fixes: 9d84c7e ("drm/amd/display: Correct cursor position on horizontal mirror")
Signed-off-by: Melissa Wen <[email protected]>
Signed-off-by: Hamza Mahfooz <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
Cc: [email protected]

Author: melissawen

drivers/gpu/drm/amd/display/dc/dcn10/dcn10_hw_sequencer.c

@@ -3626,7 +3626,7 @@ void dcn10_set_cursor_position(struct pipe_ctx *pipe_ctx)
 						(int)hubp->curs_attr.width || pos_cpy.x
 						<= (int)hubp->curs_attr.width +
 						pipe_ctx->plane_state->src_rect.x) {
-						pos_cpy.x = temp_x + viewport_width;
+						pos_cpy.x = 2 * viewport_width - temp_x;
 					}
 				}
 			} else {