[ARM] 5108/2: PXA SSP: Don't unconditionally free interrupt

Callers may stop the SSP core requesting the interrupt so it can't be
freed unconditionally.  Also use NO_IRQ like we should.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>