ARM: dts: imx31: add device tree description of basic controllers

The change adds a number of basic peripherals found on i.MX31 SoC:
* GPIO controllers,
* I2C master controllers,
* SPI master controllers,
* ATA controller,
* SDHC controllers,
* RTC, watchdog and PWM contollers,
* SDMA,
* IRAM,
* NAND and WEIM controllers on EMI.

The added controller devices were tested on Freescale i.MX31 powered
LogicPD Lite SoM and baseboard.

DMA functionality was tested on SDHC and SPI controllers so far,
thus dmas properties are added to those device nodes only.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>