misc: atsha204a: fix sleep function

Fix the sleep function to issue the sleep command instead of idle one.

Signed-off-by: Michał Barnaś <barnas@google.com>
diff --git a/drivers/misc/atsha204a-i2c.c b/drivers/misc/atsha204a-i2c.c
index ab83bbc..29daefb 100644
--- a/drivers/misc/atsha204a-i2c.c
+++ b/drivers/misc/atsha204a-i2c.c
@@ -139,7 +139,7 @@
 int atsha204a_sleep(struct udevice *dev)
 {
 	int res;
-	u8 req = ATSHA204A_FUNC_IDLE;
+	u8 req = ATSHA204A_FUNC_SLEEP;
 
 	res = atsha204a_send(dev, &req, 1);
 	if (res)