acpigen_ps2_keybd: Add support for dictation key

Some internal keyboards have a dictation key; this commit simply adds
support for this key by adding the mapping from the scancode to the
Linux keycode for use in the linux,physmap ACPI table.

BUG=b:333101631
TEST=Flash DUT that emits a scancode for a dictation key, verify that it
is mapped to KEY_DICTATE in the Linux kernel.

Change-Id: Iabc56662a9d6b29e84ab81ed93cb46d2e8372de9
Signed-off-by: Aseda Aboagye <aaboagye@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/81863
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nick Vaccaro <nvaccaro@google.com>

src/acpi/acpigen_ps2_keybd.c

@@ -56,6 +56,7 @@ static const uint32_t action_keymaps[] = {
 	[PS2_KEY_MICMUTE] = KEYMAP(0x9b, KEY_MICMUTE),			/* e01b */
 	[PS2_KEY_KBD_BKLIGHT_TOGGLE] = KEYMAP(0x9e, KEY_KBDILLUMTOGGLE),	/* e01e */
 	[PS2_KEY_MENU] = KEYMAP(0xdd, KEY_CONTROLPANEL),	/* e0d5 */
+	[PS2_KEY_DICTATE] = KEYMAP(0xa7, KEY_DICTATE),		/* e027*/
 };
 
 /* Keymap for numeric keypad keys */

src/include/acpi/acpigen_ps2_keybd.h

@@ -27,6 +27,7 @@ enum ps2_action_key {
 	PS2_KEY_KBD_BKLIGHT_TOGGLE,
 	PS2_KEY_MICMUTE,
 	PS2_KEY_MENU,
+	PS2_KEY_DICTATE,
 };
 
 #define PS2_MIN_TOP_ROW_KEYS		2