drm/amd/display: convert to use le16_add_cpu()

Convert cpu_to_le16(le16_to_cpu(E1) + E2) to use le16_add_cpu().
Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/bios/command_table.c

@@ -1877,9 +1877,7 @@ static enum bp_result set_crtc_using_dtd_timing_v3(
 			 * but it is 4 either from Edid data (spec CEA 861)
 			 * or CEA timing table.
 			 */
-			params.usV_SyncOffset =
-					cpu_to_le16(le16_to_cpu(params.usV_SyncOffset) + 1);
-
+			le16_add_cpu(&params.usV_SyncOffset, 1);
 		}
 	}
 

drivers/gpu/drm/amd/display/dc/bios/command_table2.c

@@ -569,10 +569,7 @@ static enum bp_result set_crtc_using_dtd_timing_v3(
 			 * but it is 4 either from Edid data (spec CEA 861)
 			 * or CEA timing table.
 			 */
-			params.v_syncoffset =
-				cpu_to_le16(le16_to_cpu(params.v_syncoffset) +
-						1);
-
+			le16_add_cpu(&params.v_syncoffset, 1);
 		}
 	}