Revert "drm/amd/display: cache trace buffer size"

Revert commit 257e989 ("drm/amd/display: cache trace buffer size")
to fix regression found in tests.

Acked-by: Stylon Wang <stylon.wang@amd.com>
Signed-off-by: Leo Ma <hanghong.ma@amd.com>
Reviewed-by: Josip Pavic <Josip.Pavic@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

Author: Leo Ma

drivers/gpu/drm/amd/display/dmub/dmub_srv.h

@@ -428,7 +428,6 @@ struct dmub_srv {
 	enum dmub_asic asic;
 	void *user_ctx;
 	uint32_t fw_version;
-	uint32_t trace_buffer_size;
 	bool is_virtual;
 	struct dmub_fb scratch_mem_fb;
 	volatile const struct dmub_fw_state *fw_state;

drivers/gpu/drm/amd/display/dmub/src/dmub_srv.c

@@ -427,8 +427,6 @@ dmub_srv_calc_region_info(struct dmub_srv *dmub,
 			dmub->fw_version = fw_info->fw_version;
 	}
 
-	dmub->trace_buffer_size = trace_buffer_size;
-
 	trace_buff->base = dmub_align(mail->top, 256);
 	trace_buff->top = trace_buff->base + dmub_align(trace_buffer_size, 64);