powerpc/83xx: new board support: MPC8360E-RDK

This is patch adds board file, device tree, and defconfig for the new
board, made by Freescale Semiconductor Inc. and Logic Product Development.

Currently supported:
1. UEC{1,2,7,4};
2. I2C;
3. SPI;
4. NS16550 serial;
5. PCI and miniPCI;
6. Intel NOR StrataFlash X16 64Mbit PC28F640P30T85;
7. Graphics controller, Fujitsu MB86277.

Not supported in this patch:
1. StMICRO NAND512W3A2BN6E, 512 Mbit (supported with FSL UPM NAND driver);
2. FHCI USB (supported with FHCI driver).
3. QE Serial UCCs (tested to not work with ucc_uart driver, reason
   unknown, yet);
4. ADC AD7843 (tested to work, but support via device tree depends on
   major SPI rework, GPIO API, etc);

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>