mx25: fix compile error in platform-imx-dma.c

this patch fix the following errors :
arch/arm/plat-mxc/devices/platform-imx-dma.c:44:
    error: ‘MX25_SDMA_BASE_ADDR’ undeclared here (not in a function)
arch/arm/plat-mxc/devices/platform-imx-dma.c:44:
    error: ‘MX25_INT_SDMA’ undeclared here (not in a function)

Signed-off-by: Eric Bénard <eric@eukrea.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>