drm/amd/display: Adjust cursor position

[why & how]
When the commit 9d84c7e ("drm/amd/display: Correct cursor position
on horizontal mirror") was introduced, it used the wrong calculation for
the position copy for X. This commit uses the correct calculation for that
based on the original patch.

Fixes: 9d84c7e ("drm/amd/display: Correct cursor position on horizontal mirror")
Cc: Mario Limonciello <[email protected]>
Cc: Alex Deucher <[email protected]>
Acked-by: Wayne Lin <[email protected]>
Signed-off-by: Rodrigo Siqueira <[email protected]>
Signed-off-by: Tom Chung <[email protected]>
Tested-by: Daniel Wheeler <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
(cherry picked from commit 8f9b23a)
Cc: [email protected]

Author: Rodrigo Siqueira

drivers/gpu/drm/amd/display/dc/hwss/dcn10/dcn10_hwseq.c

@@ -3682,7 +3682,7 @@ 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 = 2 * viewport_width - temp_x;
+						pos_cpy.x = temp_x + viewport_width;
 					}
 				}
 			} else {