acpigen_ps2_keybd: Support a Do Not Disturb key

This commit simply adds support for a Do Not Disturb key. HUTRR94 added
support for a new usage titled "System Do Not Disturb" which toggles a
system-wide Do Not Disturb setting.

BUG=b:342467600
TEST=Build and flash a board that generates a scancode for a Do Not
Disturb key. Verify that KEY_DO_NOT_DISTURB is generated in the Linux
kernel with patches[0] that add this new event code using `evtest`.

[0] - https://git.kernel.org/pub/scm/linux/kernel/git/hid/hid.git/commit/?id=22d6d060ac77955291deb43efc2f3f4f9632c6cb

Change-Id: I26e719bbde5106305282fe43dd15833a3e48e41e
Signed-off-by: Aseda Aboagye <aaboagye@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82997
Reviewed-by: Caveh Jalali <caveh@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Forest Mittelberg <bmbm@google.com>

src/acpi/acpigen_ps2_keybd.c

@@ -58,6 +58,7 @@ static const uint32_t action_keymaps[] = {
 	[PS2_KEY_MENU] = KEYMAP(0xdd, KEY_CONTROLPANEL),	/* e0d5 */
 	[PS2_KEY_DICTATE] = KEYMAP(0xa7, KEY_DICTATE),		/* e027*/
 	[PS2_KEY_ACCESSIBILITY] = KEYMAP(0xa9, KEY_ACCESSIBILITY),	/* e029 */
+	[PS2_KEY_DO_NOT_DISTURB] = KEYMAP(0xa8, KEY_DO_NOT_DISTURB),	/* e028 */
 };
 
 /* Keymap for numeric keypad keys */

src/ec/google/chromeec/ec_acpi.c

@@ -235,6 +235,7 @@ static const enum ps2_action_key ps2_enum_val[] = {
 	[TK_MENU] = PS2_KEY_MENU,
 	[TK_DICTATE] = PS2_KEY_DICTATE,
 	[TK_ACCESSIBILITY] = PS2_KEY_ACCESSIBILITY,
+	[TK_DONOTDISTURB] = PS2_KEY_DO_NOT_DISTURB,
 };
 
 static void fill_ssdt_ps2_keyboard(const struct device *dev)

src/include/acpi/acpigen_ps2_keybd.h

@@ -29,6 +29,7 @@ enum ps2_action_key {
 	PS2_KEY_MENU,
 	PS2_KEY_DICTATE,
 	PS2_KEY_ACCESSIBILITY,
+	PS2_KEY_DO_NOT_DISTURB,
 };
 
 #define PS2_MIN_TOP_ROW_KEYS		2