drm/amd/display: Fix number of slices not being checked for dsc

[why]
num_slices_h was not being checked

[How]
Fix the typo and check num_slices_h
Signed-off-by: Nikola Cornij <nikola.cornij@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Acked-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dcn20/dcn20_dsc.c

@@ -322,7 +322,7 @@ static bool dsc_prepare_config(const struct dsc_config *dsc_cfg, struct dsc_reg_
 		    dsc_cfg->dc_dsc_cfg.linebuf_depth == 0)));
 	ASSERT(96 <= dsc_cfg->dc_dsc_cfg.bits_per_pixel && dsc_cfg->dc_dsc_cfg.bits_per_pixel <= 0x3ff); // 6.0 <= bits_per_pixel <= 63.9375
 
-	if (!dsc_cfg->dc_dsc_cfg.num_slices_v || !dsc_cfg->dc_dsc_cfg.num_slices_v ||
+	if (!dsc_cfg->dc_dsc_cfg.num_slices_v || !dsc_cfg->dc_dsc_cfg.num_slices_h ||
 		!(dsc_cfg->dc_dsc_cfg.version_minor == 1 || dsc_cfg->dc_dsc_cfg.version_minor == 2) ||
 		!dsc_cfg->pic_width || !dsc_cfg->pic_height ||
 		!((dsc_cfg->dc_dsc_cfg.version_minor == 1 && // v1.1 line buffer depth range: