mfd: arizona-core: msleep() is unreliable for anything <20ms use usleep_range() instead

WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+               msleep(1);

WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+                       msleep(5);

WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+               msleep(1);

WARNING: msleep < 20ms can sleep for up to 20ms; see Documentation/timers/timers-howto.txt
+               msleep(1);

total: 0 errors, 4 warnings, 1407 lines checked

Cc: patches@opensource.wolfsonmicro.com
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
index 4bb4866..5319f25 100644
--- a/drivers/mfd/arizona-core.c
+++ b/drivers/mfd/arizona-core.c
@@ -238,7 +238,7 @@
 		if ((val & mask) == target)
 			return 0;
 
-		msleep(1);
+		usleep_range(1000, 5000);
 	}
 
 	dev_err(arizona->dev, "Polling reg %u timed out: %x\n", reg, val);
@@ -279,14 +279,14 @@
 		case WM5110:
 		case WM8280:
 			/* Meet requirements for minimum reset duration */
-			msleep(5);
+			usleep_range(5000, 10000);
 			break;
 		default:
 			break;
 		}
 
 		gpio_set_value_cansleep(arizona->pdata.reset, 1);
-		msleep(1);
+		usleep_range(1000, 5000);
 	}
 }
 
@@ -1132,7 +1132,7 @@
 			goto err_reset;
 		}
 
-		msleep(1);
+		usleep_range(1000, 5000);
 	}
 
 	/* Ensure device startup is complete */