ACPICA: executer/exsystem: Add units to time variable names

ACPICA commit b69cbef7a83eadb102a1ff6c6f6fc5abce34805a

`how_long` refers to different units in both functions, so make it more
clear, what unit they expect. That also makes one comment superfluous.

Link: https://github.com/acpica/acpica/commit/b69cbef7
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/acpi/acpica/exsystem.c

@@ -107,7 +107,7 @@ acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
  *
  * FUNCTION:    acpi_ex_system_do_stall
  *
- * PARAMETERS:  how_long        - The amount of time to stall,
+ * PARAMETERS:  how_long_us     - The amount of time to stall,
  *                                in microseconds
  *
  * RETURN:      Status
@@ -120,24 +120,24 @@ acpi_status acpi_ex_system_wait_mutex(acpi_mutex mutex, u16 timeout)
  *
  ******************************************************************************/
 
-acpi_status acpi_ex_system_do_stall(u32 how_long)
+acpi_status acpi_ex_system_do_stall(u32 how_long_us)
 {
 	acpi_status status = AE_OK;
 
 	ACPI_FUNCTION_ENTRY();
 
-	if (how_long > 255) {	/* 255 microseconds */
+	if (how_long_us > 255) {
 		/*
-		 * Longer than 255 usec, this is an error
+		 * Longer than 255 microseconds, this is an error
 		 *
 		 * (ACPI specifies 100 usec as max, but this gives some slack in
 		 * order to support existing BIOSs)
 		 */
 		ACPI_ERROR((AE_INFO,
-			    "Time parameter is too large (%u)", how_long));
+			    "Time parameter is too large (%u)", how_long_us));
 		status = AE_AML_OPERAND_VALUE;
 	} else {
-		acpi_os_stall(how_long);
+		acpi_os_stall(how_long_us);
 	}
 
 	return (status);
@@ -147,7 +147,7 @@ acpi_status acpi_ex_system_do_stall(u32 how_long)
  *
  * FUNCTION:    acpi_ex_system_do_sleep
  *
- * PARAMETERS:  how_long        - The amount of time to sleep,
+ * PARAMETERS:  how_long_ms     - The amount of time to sleep,
  *                                in milliseconds
  *
  * RETURN:      None
@@ -156,7 +156,7 @@ acpi_status acpi_ex_system_do_stall(u32 how_long)
  *
  ******************************************************************************/
 
-acpi_status acpi_ex_system_do_sleep(u64 how_long)
+acpi_status acpi_ex_system_do_sleep(u64 how_long_ms)
 {
 	ACPI_FUNCTION_ENTRY();
 
@@ -168,11 +168,11 @@ acpi_status acpi_ex_system_do_sleep(u64 how_long)
 	 * For compatibility with other ACPI implementations and to prevent
 	 * accidental deep sleeps, limit the sleep time to something reasonable.
 	 */
-	if (how_long > ACPI_MAX_SLEEP) {
-		how_long = ACPI_MAX_SLEEP;
+	if (how_long_ms > ACPI_MAX_SLEEP) {
+		how_long_ms = ACPI_MAX_SLEEP;
 	}
 
-	acpi_os_sleep(how_long);
+	acpi_os_sleep(how_long_ms);
 
 	/* And now we must get the interpreter again */