[ARM] pxa/pcm027: convert to use new MFP API

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Acked-by: Guennadi Liakhovetski <g.liakhovetski@pengutronix.de>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>