arm: Note vendor-required status of certain MACH_TYPE values

arm: Note vendor-required status of certain MACH_TYPE values

In the cases of some boards, a MACH_TYPE number is used which is either
not registered upstream or worse (for functionality) is re-using the
number of a different (or reference) platform instead.  Make sure we
have a comment in these cases.

Cc: Albert ARIBAUD <[email protected]>
Cc: Walter Schweizer <[email protected]>
Cc: Stefan Roese <[email protected]>
Cc: Fabio Estevam <[email protected]>
Signed-off-by: Tom Rini <[email protected]>
Acked-by: Stefan Roese <[email protected]>