acpigen_ps2_keybd: map screenlock

This is going to be used by some devices, map the next available
extended code to it.

Change-Id: Ib4fc6c33e10f273a73f3a6ca40deeefa3ab70f20
Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/90617
Reviewed-by: Subrata Banik <subratabanik@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/acpi/acpigen_ps2_keybd.c

@@ -179,6 +179,8 @@ static uint32_t rest_of_keymaps[] = {
 	KEYMAP(0x3a, KEY_CAPSLOCK),
 	/* Insert Key */
 	KEYMAP(0xd2, KEY_INSERT),
+	/* Screen Lock */
+	KEYMAP(0xab, KEY_SCREENLOCK),
 };
 
 static void ssdt_generate_physmap(struct acpi_dp *dp, uint8_t num_top_row_keys,