libpayload/i8042: Increase response timeout to 1.5s

The current timeout of 500ms is too low. For instance self-test
of the KBC integrated into IT8516E took almost 1s in tests. We
already check for presence of the KBC before the self-test. So
the timeout should only trigger on a hardware defect and we can
leave some margin.

Change-Id: I95f01a4e605a9c7deb894a71e102c3a881759bb1
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47588
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

payloads/libpayload/drivers/i8042/i8042.c

@@ -159,7 +159,7 @@ static u8 i8042_wait_cmd_rdy(void)
  */
 static u8 i8042_wait_data_rdy(void)
 {
-	int retries = 10000;
+	int retries = 30000;
 	while (retries-- && !(read_status() & OBF))
 		udelay(50);