ARM: 5798/1: SA1100: h3600: remove unused cruft from h3600.h

PM_SUSPEND, PM_RESUME and machine_is_h3xxx() are not used anywhere in
kernel (checked with git grep), so it's safe to remove them.

Signed-off-by: Dmitry Artamonow <mad_soft@inbox.ru>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>