ACPI / button: Using input_set_capability() to mark device's event capability

Input layer provides input_set_capability() to set input device's event
related bits. This patch is to use it to replace origin code.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/acpi/button.c b/drivers/acpi/button.c
index a557738..c971929 100644
--- a/drivers/acpi/button.c
+++ b/drivers/acpi/button.c
@@ -383,18 +383,15 @@
 
 	switch (button->type) {
 	case ACPI_BUTTON_TYPE_POWER:
-		input->evbit[0] = BIT_MASK(EV_KEY);
-		set_bit(KEY_POWER, input->keybit);
+		input_set_capability(input, EV_KEY, KEY_POWER);
 		break;
 
 	case ACPI_BUTTON_TYPE_SLEEP:
-		input->evbit[0] = BIT_MASK(EV_KEY);
-		set_bit(KEY_SLEEP, input->keybit);
+		input_set_capability(input, EV_KEY, KEY_SLEEP);
 		break;
 
 	case ACPI_BUTTON_TYPE_LID:
-		input->evbit[0] = BIT_MASK(EV_SW);
-		set_bit(SW_LID, input->swbit);
+		input_set_capability(input, EV_SW, SW_LID);
 		break;
 	}