mpq101: initial support for Mercury Computer Systems MPQ101 board

Mpq101 is a RapidIO development board in AMC form factor, featuring MPC8548
processor, 512MB of hardwired DDR2 RAM, 128MB of hardwired NAND flash
memory, real time clock and additional serial EEPROM on i2c bus (enabled).
USB controller is available, but not presently enabled.

Additional board information is available at:
http://www.mc.com/products/boards/ensemble_mpq101_rapidio_powerquicc_iii.aspx



Environment is configured to precede the actual u-boot image so that it's
located at the beginning of flash erase block (made necessary by the recent
changes to the embedded environment handling). This is achieved by means of
custom ld script.

Signed-off-by: Alex Dubov <oakad@yahoo.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>