libpayload/keyboard: Reset to scancode set #2 on exit

If we select scancode set #1 and keep that, it can confuse Linux
with keyboards that don't return to set #2 when asked to load the
defaults. This happens for instance with various integrated Think-
Pad keyboards but was also seen with an external PS/2 one.

The chosen configuration, scancode set #2 without translation, seems
to be the default for many systems. So we can expect other payloads
and kernels to work with it.

Change-Id: I28d74590e9f04d32bb2bbd461b67f15014f927ec
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47594
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

payloads/libpayload/drivers/i8042/keyboard.c

@@ -655,6 +655,11 @@ void keyboard_disconnect(void)
 	keyboard_cmd(I8042_KBCMD_DEFAULT_DIS);
 	keyboard_drain_input();
 
+	/* Nobody but us seems to still use scancode set #1.
+	   So try to hand over with more modern settings. */
+	set_scancode_set(2);
+	i8042_set_kbd_translation(false);
+
 	/* Send keyboard disconnect command */
 	i8042_cmd(I8042_CMD_DIS_KB);