uboot-imx

AVR32: Use initdram() instead of board_init_memories()

Conform to the "standard" interface and use initdram() instead of
board_init_memories() on AVR32. This enables us to get rid of the
sdram_size member of the global_data struct as well.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>