ARM: sa11x0: neponset: suspend/resume in _noirq state

Suspend and resume in the _noirq state, so that we're saving the
state of the modem control signals as late as possible, and restoring
them as early as possible.  There's nothing to do in thaw/poweroff
methods as we've already saved the necessary state.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>