mb/google/deltaur: Enable PS/2 keyboard

By default, the ACPI status method _STA returns false for the PS/2
keyboard and mouse device of the Wilco EC, so the OS does not enable it.
Enable these devices, by defining the macro SIO_EC_ENABLE_PS2K.

BUG=b:154790509
TEST=Check Keyboard is functional under OS.

Signed-off-by: Eric Lai <ericr_lai@compal.corp-partner.google.com>
Change-Id: I31c74ddb3608589e5a4753c7e487f250b112bb1e
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40745
Reviewed-by: Ivy Jian <ivy_jian@compal.corp-partner.google.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/deltaur/variants/baseboard/include/baseboard/ec.h

@@ -7,8 +7,7 @@
 #ifndef __MAINBOARD_EC_H__
 #define __MAINBOARD_EC_H__
 
-
-
-
+/* Enable PS/2 keyboard */
+#define SIO_EC_ENABLE_PS2K
 
 #endif /* __MAINBOARD_EC_H__ */