drm/amd: add missing fill of the array`s first element

In function fill_iram_v_2, the ram_table->bright_neg_gain`s
first element [0][0] seems to be missing. This change is just
to make the code a bit readable.
Signed-off-by: Bernard Zhao <bernard@vivo.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/modules/power/power_helpers.c

@@ -353,6 +353,7 @@ void fill_iram_v_2(struct iram_table_v_2 *ram_table, struct dmcu_iram_parameters
 	ram_table->bright_pos_gain[4][1] = 0x20;
 	ram_table->bright_pos_gain[4][2] = 0x20;
 	ram_table->bright_pos_gain[4][3] = 0x20;
+	ram_table->bright_neg_gain[0][0] = 0x00;
 	ram_table->bright_neg_gain[0][1] = 0x00;
 	ram_table->bright_neg_gain[0][2] = 0x00;
 	ram_table->bright_neg_gain[0][3] = 0x00;