i.MX2: Include asm/types.h in arch-mx25/imx-regs.h

i.MX2: Include asm/types.h in arch-mx25/imx-regs.h

types.h must be included in imx-regs.h if one wants to include
imx-regs.h in a board configuration file. That for one's part is
necessary, if one wants to use addresses defined in imx-regs.h.

For example, fsl_esdhc.c needs CONFIG_SYS_FSL_ESDHC_ADDR defined and
a proper thing is to define it with IMX_MMC_SDHCx_BASE in board
configuration file. This patch fixes the build in that case.

Signed-off-by: Timo Ketola <timo@exertus.fi>
Acked-by: Stefano Babic <sbabic@denx.de>