powerpc/5121: add initial support for PDM360NG board

Adds IFM PDM360NG device tree and platform code.

Currently following is supported:
 - Spansion S29GL512P 256 MB NOR flash
 - ST Micro NAND 1 GiB flash
 - DIU, please use "fbcon=map:5 video=fslfb:800x480-32@60"
   at the kernel command line to enable PrimeView PM070WL3
   Display support.
 - FEC
 - I2C
 - RTC, EEPROM
 - MSCAN
 - PSC UART, please pass "console=tty0 console=ttyPSC5,115200"
   on the kernel command line.
 - SPI, ADS7845 Touchscreen
 - USB0/1 Host
 - USB0 OTG Host/Device
 - VIU, Overlay/Capture support

Signed-off-by: Markus Fischer <markus.fischer.ec@ifm.com>
Signed-off-by: Wolfgang Grandegger <wg@denx.de>
Signed-off-by: Michael Weiss <michael.weiss@ifm.com>
Signed-off-by: Detlev Zundel <dzu@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>