drm/amd/display: Fix DC warning at driver load

[Why]
Wrong index was checked for dcfclk_mhz, causing false warning.

[How]
Fix the assertion index.
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Dmytro Laktyushkin <Dmytro.Laktyushkin@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/clk_mgr/dcn315/dcn315_clk_mgr.c

@@ -550,7 +550,7 @@ static void dcn315_clk_mgr_helper_populate_bw_params(
 		if (!bw_params->clk_table.entries[i].dtbclk_mhz)
 			bw_params->clk_table.entries[i].dtbclk_mhz = def_max.dtbclk_mhz;
 	}
-	ASSERT(bw_params->clk_table.entries[i].dcfclk_mhz);
+	ASSERT(bw_params->clk_table.entries[i-1].dcfclk_mhz);
 	bw_params->vram_type = bios_info->memory_type;
 	bw_params->num_channels = bios_info->ma_channel_number;
 	if (!bw_params->num_channels)