bus: ti-sysc: Use fsleep() instead of usleep_range() in sysc_reset()

The am335x-evm started producing boot errors because of subtle timing
changes:

Unhandled fault: external abort on non-linefetch (0x1008) at 0xf03c1010
...
sysc_reset from sysc_probe+0xf60/0x1514
sysc_probe from platform_probe+0x5c/0xbc
...

The fix consists in using the appropriate sleep function in sysc reset.
For flexible sleeping, fsleep is recommended. Here, sysc delay parameter
can take any value in [0 - 255] us range. As a result, fsleep() should
be used, calling udelay() for a sysc delay lower than 10 us.

Signed-off-by: Julien Panis <[email protected]>
Fixes: e709ed7 ("bus: ti-sysc: Fix missing reset delay handling")
Message-ID: <[email protected]>
Signed-off-by: Tony Lindgren <[email protected]>

Author: jpanisbl

drivers/bus/ti-sysc.c

@@ -2150,8 +2150,7 @@ static int sysc_reset(struct sysc *ddata)
 	}
 
 	if (ddata->cfg.srst_udelay)
-		usleep_range(ddata->cfg.srst_udelay,
-			     ddata->cfg.srst_udelay * 2);
+		fsleep(ddata->cfg.srst_udelay);
 
 	if (ddata->post_reset_quirk)
 		ddata->post_reset_quirk(ddata);