reboot: arm: remove unused restart_mode fields from some arm subarchs

reboot: arm: remove unused restart_mode fields from some arm subarchs

These restart_mode fields are not used at all.  Remove them to make
moving the reboot= cmdline options to the general kernel easier.

Signed-off-by: Robin Holt <[email protected]>
Cc: Russell King <[email protected]>
Cc: Russ Anderson <[email protected]>
Cc: Robin Holt <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: Guan Xuetao <[email protected]>
Acked-by: Russell King <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>