ARM: mx3/pcm037: properly allocate memory for mx3-camera

There is no need to memzero the buffer because dma_alloc_coherent zeros
the memory for us.

This fixes:

	BUG: Your driver calls ioremap() on system memory.  This leads
	<4>to architecturally unpredictable behaviour on ARMv6+, and ioremap()
	<4>will fail in the next kernel release.  Please fix your driver.

Tested-by: Michael Grzeschik <mgr@pengutronix.de>
LAKML-Reference: 1299271882-2130-3-git-send-email-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>