pc: add option to disable PS/2 mouse/keyboard

pc: add option to disable PS/2 mouse/keyboard

On some older software like Windows 7 installer, having both a PS/2
mouse and USB mouse results in only one device working property (which
might be a different device each boot). While the workaround to not use
a USB mouse with such software is valid, it creates an inconsistent
experience if the user wishes to always use a USB mouse.

This introduces a new machine property to inhibit the creation of the
i8042 PS/2 controller.

Signed-off-by: Joelle van Dyne <j@getutm.app>
Message-Id: <20220227210655.45592-1-j@getutm.app>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>