FROMLIST: ufs: core: fix abnormal scale up after last cmd finish

When ufshcd_clk_scaling_suspend_work(Thread A) running and new command
coming, ufshcd_clk_scaling_start_busy(Thread B) may get host_lock
after Thread A first time release host_lock. Then Thread A second time
get host_lock will set clk_scaling.window_start_t = 0 which scale up
clock abnormal next polling_ms time.
Also inlines another __ufshcd_suspend_clkscaling calls.

Below is racing step:
1	hba->clk_scaling.suspend_work (Thread A)
	ufshcd_clk_scaling_suspend_work
2		spin_lock_irqsave(hba->host->host_lock, irq_flags);
3		hba->clk_scaling.is_suspended = true;
4		spin_unlock_irqrestore(hba->host->host_lock, irq_flags);
		__ufshcd_suspend_clkscaling
7			spin_lock_irqsave(hba->host->host_lock, flags);
8			hba->clk_scaling.window_start_t = 0;
9			spin_unlock_irqrestore(hba->host->host_lock, flags);

	ufshcd_send_command (Thread B)
		ufshcd_clk_scaling_start_busy
5			spin_lock_irqsave(hba->host->host_lock, flags);
			....
6			spin_unlock_irqrestore(hba->host->host_lock, flags);

Bug: 298004596
Link: https://lore.kernel.org/all/20230831130826.5592-3-peter.wang@mediatek.com/


Change-Id: Ib208b1265107769005c4ae3f72d46b12c072b5c7
Signed-off-by: Peter Wang <peter.wang@mediatek.com>