ARM: dts: imx7: add GPMI NAND and APBH DMA

Add i.MX 7 APBH DMA and GPMI NAND modules.

Signed-off-by: Stefan Agner <stefan@agner.ch>
Tested-by: Fabio Estevam <fabio.estevam@nxp.com>
Acked-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>