drm/amd/display: Restore should_update_pstate_support after bad revert

[Why]
This function was mistakenly reverted as part of a legitimate revert. The
old version that was reverted to has bad logic, and is causing situations
where p-state change support is being toggled when it shouldn't be,
resulting in hangs.
Signed-off-by: Joshua Aberback <joshua.aberback@amd.com>
Reviewed-by: Jun Lei <Jun.Lei@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/inc/hw/clk_mgr_internal.h

@@ -281,8 +281,14 @@ static inline bool should_set_clock(bool safe_to_lower, int calc_clk, int cur_cl
 
 static inline bool should_update_pstate_support(bool safe_to_lower, bool calc_support, bool cur_support)
 {
-	// Whenever we are transitioning pstate support, we always want to notify prior to committing state
-	return (calc_support != cur_support) ? !safe_to_lower : false;
+	if (cur_support != calc_support) {
+		if (calc_support == true && safe_to_lower)
+			return true;
+		else if (calc_support == false && !safe_to_lower)
+			return true;
+	}
+
+	return false;
 }
 
 int clk_mgr_helper_get_active_display_cnt(