HID: Add map_msc() to avoid boilerplate code

Since we are going to have more MSC events too, add map_msc() that can
be used to fill in necessary fields and avoid boilerplate code.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20211210111138.1248187-2-tero.kristo@linux.intel.com